The last year can be described as another turbulent year in the cybersecurity sector, with high-profile ransomware incidents and supply chain attacks making national headlines. While the Trustwave SpiderLabs offered amazing insight on almost all these issues, the team also continued its hard work conducting breakthrough research on a wide array of vulnerabilities and malware.

Please take a look below at the Top 10 Trustwave SpiderLabs blog posts from 2021 ranked by readership.

Full System Control with New SolarWinds Orion-based and Serv-U FTP Vulnerabilities---

Martin Rakhmanov, Security Research Manager, Trustwave, in a Feb. 3 blog, discussed his research into three new security issues he found in several SolarWinds products. All three were severe bugs, with the most critical one allowing remote code execution with high privileges.

A Trump Sex Video? No, It's a RAT!

While reviewing Trustwave SpiderLabs spam traps, Diana Lopera, Senior Security Researcher, Trustwave, came across a particular campaign that piqued her interest. A topic she blogged on in January. Oddly, the email’s attachment did not coincide with the theme of the email body. She discovered that its attachment is a variant of the QRAT downloader that the team blogged about in August 2020 when Trustwave SpiderLabs investigated that malware.

Pingback: Backdoor At The End Of The ICMP Tunnel

In this May 2021 post, Trustwave’s Lloyd Macrohon, Senior Architect, and Rodel Mendrez, Principal Security Researcher, analyzed a newly discovered piece of malware that the team encountered during a breach investigation. What caught their attention was how the malware achieved persistence, used ICMP tunneling for its backdoor communications, and how it operated with different modes to increase its chances of a successful attack. The duo named this malware ‘Pingback’.

BlackByte Ransomware – An-depth Analysis

In October, Macrohon and Mendrez took a long look at BlackByte ransomware in a two-part blog. In the blog the two reported that Trustwave SpiderLabs team posted a free decryptor allowing BlackByte ransomware victims to recover their data. In part one of the blog, the pair’s analysis also covered the execution flow of the malware’s first stage JScript launcher, how the team extracted BlackByte’s binary from the second stage Dynamic Link Library (DLL), and the inner workings of the ransomware.

In part two (BlackByte Ransomware – Pt 2. Code Obfuscation Analysis), Macrohon and Mendrez detailed how they analyzed and de-obfuscated the JScript launcher, BlackByte’s code, and strings.

Diving Deeper Into the Kaseya VSA Attack: REvil Returns and Other Hackers Are Riding Their Coattails

On July 2, a massive ransomware attack was launched against roughly 60 managed services providers (MSPs) by criminals associated with the REvil ransomware-as-a-service (RaaS) group. The Trustwave SpiderLabs team posted an in-depth look at that attack just five days later with Mendrez, and Nikita Kazymirskyi, Security Researcher. Trustwave, writing how the REvil ransomware group had found and leveraged an unpatched zero-day vulnerability in Kaseya's VSA software.

HAFNIUM, China Chopper and ASP.NET Runtime

In the aftermath of the March 2021 Microsoft Exchange Server zero-day attacks, which resulted in tens of thousands of organizations compromised by the cyber threat group HAFNIUM and other threat actors, Trustwave worked closely with our customers across the globe, to quickly identify and isolate attributes of those attacks. Joshua Deacon, Security Researcher - Email Security and Malware Analysis, Trustwave, in a March blog detailed the China Chopper web shell being uploaded to compromised Microsoft Exchange servers with a publicly facing Internet Information Services (IIS) web server.

HTML Lego: Hidden Phishing at Free JavaScript Site

In April, Homer Pacag, Malware Analyst and Tools Developer, Trustwave, blogged about an investigation Trustwave SpiderLabs conducted into a phishing campaign with the odd email subject line “Price Revision 849604” and no body text. If successful, the malware steals a variety of information, including email addresses, passwords, and additional credentials. Pacq noted this phishing campaign’s design was somewhat unique. By improvising an HTML email attachment that incorporates remote JavaScript code located on a free JavaScript hosting site, and ensuring the code is encoded uniquely, the attackers seek to fly under the radar to avoid detection.

Telegram Self-Destruct? Not Always

Encrypted Telegram chats might not be as private as users think, according to an August blog by Reegun Jayapaul, Lead Threat Architect, Trustwave SpiderLabs. Reegun was able to identify the privacy flaws in Telegram's self-destruct chats. He found a person can retrieve audio, video messages, shared locations, and files even after the self-destruct feature works on both devices because, by default, any media files, except attachments, sent to Telegram are downloaded to the above cache folder. In addition, the app stores shared locations as a picture.

Yet Another Archive Format Smuggling Malware

In June Diana Lopera, Senior Security Researcher, Trustwave, blogged about cybercriminals using a new image file format to obfuscate malware. These spam emails, spoofing courier companies, she wrote, contain a malicious WIM (Windows Imaging Format) file disguised as an invoice or consignment note. In addition, the emails contain the Remote Access Trojan (RAT) Agent Tesla, which has the ability to take full control of a compromised system and exfiltrate data via HTTP, SMTP, FTP, and Telegram.