Nascan是巡风主要是做目标的资产识别(信息收集)。

nascan.py 文件位于 nascan/nascan.py

# coding:utf-8
# author:[email protected]
import thread
from lib.common import *
from lib.start import *
if __name__ == "__main__":
    try:
        CONFIG_INI = get_config()  # 读取配置
        log.write('info', None, 0, u'获取配置成功')
        STATISTICS = get_statistics()  # 读取统计信息
        MASSCAN_AC = [0]
        NACHANGE = [0]
        thread.start_new_thread(monitor, (CONFIG_INI,STATISTICS,NACHANGE))  # 心跳线程
        thread.start_new_thread(cruise, (STATISTICS,MASSCAN_AC))  # 失效记录删除线程
        socket.setdefaulttimeout(int(CONFIG_INI['Timeout']) / 2)  # 设置连接超时
        ac_data = []
        while True:
            now_time = time.localtime()
            now_hour = now_time.tm_hour
            now_day = now_time.tm_mday
            now_date = str(now_time.tm_year) + str(now_time.tm_mon) + str(now_day)
            cy_day, ac_hour = CONFIG_INI['Cycle'].split('|')
            log.write('info', None, 0, u'扫描规则: ' + str(CONFIG_INI['Cycle']))
            if (now_hour == int(ac_hour) and now_day % int(cy_day) == 0 and now_date not in ac_data) or NACHANGE[0]:  # 判断是否进入扫描时段
                ac_data.append(now_date)
                NACHANGE[0] = 0
                log.write('info', None, 0, u'开始扫描')
                s = start(CONFIG_INI)
                s.masscan_ac = MASSCAN_AC
                s.statistics = STATISTICS
                s.run()
            time.sleep(60)
    except Exception, e:
        print e

读取了配置，get_config() 跟进去

nascan/lib/common.py

def get_config():
    config = {}
    config_info = mongo.na_db.Config.find_one({"type": "nascan"})
    for name in config_info['config']:
        if name in ['Discern_cms', 'Discern_con', 'Discern_lang', 'Discern_server']:
            config[name] = format_config(name, config_info['config'][name]['value'])
        else:
            config[name] = config_info['config'][name]['value']
    return config

就是读取了mongodb里面Config表下的内容。

回到nascan.py

get_statistics()则是读取统计信息，返回时间。

也是位于nascan/lib/common.py

def get_statistics():
    date_ = datetime.datetime.now().strftime('%Y-%m-%d')
    now_stati = mongo.na_db.Statistics.find_one({"date": date_})
    if not now_stati:
        now_stati = {date_: {"add": 0, "update": 0, "delete": 0}}
        return now_stati
    else:
        return {date_: now_stati['info']}

MASSCAN_AC 是系统来判断是否支持masscan扫描。为1的话就是masscan正在扫描。

 NACHANGE 是用来看现在的扫描列表和开始的列表有没有变化,有变化设为1。

thread.start_new_thread(monitor, (CONFIG_INI,STATISTICS,NACHANGE))  # 心跳线程
thread.start_new_thread(cruise, (STATISTICS,MASSCAN_AC))  # 失效记录删除线程
socket.setdefaulttimeout(int(CONFIG_INI['Timeout']) / 2)  # 设置连接超时

进入monitor心跳线程

位于nascan/lib/common.py

def monitor(CONFIG_INI, STATISTICS, NACHANGE):
    while True:
        try:
            time_ = datetime.datetime.now()
            date_ = time_.strftime('%Y-%m-%d')
            mongo.na_db.Heartbeat.update({"name": "heartbeat"}, {"$set": {"up_time": time_}})
            if date_ not in STATISTICS: STATISTICS[date_] = {"add": 0, "update": 0, "delete": 0}
            mongo.na_db.Statistics.update({"date": date_}, {"$set": {"info": STATISTICS[date_]}}, upsert=True)
            new_config = get_config()
            if base64.b64encode(CONFIG_INI["Scan_list"]) != base64.b64encode(new_config["Scan_list"]):NACHANGE[0] = 1
            CONFIG_INI.clear()
            CONFIG_INI.update(new_config)
        except Exception, e:
            print e
        time.sleep(30)

再次调用了get_config()，获取了配置信息，如果Config表的base64编码值如果有变化将NACHANGE[0]改成NACHANGE[1]。系统更新config,然后睡眠30秒，表示需要重新扫描。

返回nascan.py

Cruise()函数，位于nascan/lib/common.py

def cruise(STATISTICS,MASSCAN_AC):
    while True:
        now_str = datetime.datetime.now()
        week = int(now_str.weekday())
        hour = int(now_str.hour)
        if week >= 1 and week <= 5 and hour >= 9 and hour <= 18:  # 非工作时间不删除
            try:
                data = mongo.NA_INFO.find().sort("time", 1)
                for history_info in data:
                    while True:
                        if MASSCAN_AC[0]:  # 如果masscan正在扫描即不进行清理
                            time.sleep(10)
                        else:
                            break
                    ip = history_info['ip']
                    port = history_info['port']
                    try:
                        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                        sock.connect((ip, int(port)))
                        sock.close()
                    except Exception, e:
                        time_ = datetime.datetime.now()
                        date_ = time_.strftime('%Y-%m-%d')
                        mongo.NA_INFO.remove({"ip": ip, "port": port})
                        log.write('info', None, 0, '%s:%s delete' % (ip, port))
                        STATISTICS[date_]['delete'] += 1
                        del history_info["_id"]
                        history_info['del_time'] = time_
                        history_info['type'] = 'delete'
                        mongo.NA_HISTORY.insert(history_info)
            except:
                pass
        time.sleep(3600)

记录失效目标并删除线程，对目标（ip:port）进行sock连接,如果连接不上就删除INFO里面ip和port。然后写进history表里。

回到nascan.py

if (now_hour == int(ac_hour) and now_day % int(cy_day) == 0 and now_date not in ac_data) or NACHANGE[0]:  # 判断是否进入扫描时段

(now_hour == int(ac_hour) and now_day % int(cy_day) == 0 and now_date not in ac_data)

是判断是否到达扫描的周期时间。

或者就是NACHANGE[0]的值为1，任何一个成立都可以重新扫描。

进入Start()函数

nascan/lib/start.py

在start类中，__init__初始化了传递过来的配置信息。直接看run()，处理目标IP地址和使用masscan进行初步扫描等。

def run(self):
    global AC_PORT_LIST
    all_ip_list = []
    for ip in self.scan_list:
        if "/" in ip: ip = cidr.CIDR(ip)
        if not ip:continue
        ip_list = self.get_ip_list(ip)
        for white_ip in self.white_list:
            if white_ip in ip_list:
                ip_list.remove(white_ip)
        if self.mode == 1:
            self.masscan_path = self.config_ini['Masscan'].split('|')[2]
            self.masscan_rate = self.config_ini['Masscan'].split('|')[1]
            ip_list = self.get_ac_ip(ip_list)
            self.masscan_ac[0] = 1
            AC_PORT_LIST = self.masscan(ip_list)  # 如果安装了Masscan即使用Masscan进行全端口扫描
            if not AC_PORT_LIST: continue
            self.masscan_ac[0] = 0
            for ip_str in AC_PORT_LIST.keys(): self.queue.put(ip_str)  # 加入队列
            self.scan_start()  # 开始扫描
        else:
            all_ip_list.extend(ip_list)
    if self.mode == 0:
        if self.icmp: all_ip_list = self.get_ac_ip(all_ip_list)
        for ip_str in all_ip_list: self.queue.put(ip_str)  # 加入队列
        self.scan_start()  # TCP探测模式开始扫描

if "/" in ip: ip = cidr.CIDR(ip) ，支持这样的格式：127.0.0.1/24

if self.mode == 1 判断是否支持masscan扫描,如果支持就使用Masscan进行全端口扫描。如果没有开启，将ip添加到all_ip_list这个列表中。

跟masscan()函数

nascan/lib/start.py

def masscan(self, ip):
    try:
        if len(ip) == 0: return
        sys.path.append(sys.path[0] + "/plugin")
        m_scan = __import__("masscan")
        result = m_scan.run(ip, self.masscan_path, self.masscan_rate)
        return result
    except Exception, e:
        print e
        print 'No masscan plugin detected'

调用了/plugin/masscan.py

def run(ip_list,path,rate):
    try:
        ip_file = open('target.log','w')
        ip_file.write("\n".join(ip_list))
        ip_file.close()
        path = str(path).translate(None, ';|&')
        rate = str(rate).translate(None, ';|&')
        if not os.path.exists(path):return
        os.system("%s -p1-65535 -iL target.log -oL tmp.log --randomize-hosts --rate=%s"%(path,rate))
        result_file = open('tmp.log', 'r')
        result_json = result_file.readlines()
        result_file.close()
        del result_json[0]
        del result_json[-1]
        open_list = {}
        for res in result_json:
            try:
                ip = res.split()[3]
                port = res.split()[2]
                if ip in open_list:
                    open_list[ip].append(port)
                else:
                    open_list[ip] = [port]
            except:pass
        os.remove('target.log')
        os.remove('tmp.log')
        return open_list
    except:
        pass

先过滤了;|&三个特殊字符。然后拼接到命令中

masscan -p1-65535 -iL target.log -oL tmp.log --randomize-hosts --rate=20000

用masscan扫描好了后保存tmp.log文件里然后读取结果。

不管开没开masscan，都会进入scan_start()。

跟进到ThreadNum，位于/nascan/lib/start.py 

class ThreadNum(threading.Thread):
    def __init__(self, queue):
        threading.Thread.__init__(self)
        self.queue = queue

    def run(self):
        while True:
            try:
                task_host = self.queue.get(block=False)
            except:
                break
            try:
                if self.mode:
                    port_list = AC_PORT_LIST[task_host]
                else:
                    port_list = self.config_ini['Port_list'].split('|')[1].split('\n')
                _s = scan.scan(task_host, port_list)
                _s.config_ini = self.config_ini  # 提供配置信息
                _s.statistics = self.statistics  # 提供统计信息
                _s.run()
            except Exception, e:
                print e
            finally:
                self.queue.task_done()

run()函数，把IP地址和端口号列表传到另一个scan()函数中。

位于/nascan/lib/scan.py

class scan:
    def __init__(self, task_host, port_list):
        self.ip = task_host
        self.port_list = port_list
        self.config_ini = {}

    def run(self):
        self.timeout = int(self.config_ini['Timeout'])
        for _port in self.port_list:
            self.server = ''
            self.banner = ''
            self.port = int(_port)
            self.scan_port()  # 端口扫描
            if not self.banner:continue
            self.server_discern()  # 服务识别
            if self.server == '':
                web_info = self.try_web()  # 尝试web访问
                if web_info:
                    log.write('web', self.ip, self.port, web_info)
                    time_ = datetime.datetime.now()
                    mongo.NA_INFO.update({'ip': self.ip, 'port': self.port},
                                         {"$set": {'banner': self.banner, 'server': 'web', 'webinfo': web_info,
                                                   'time': time_}})

scan类的run函数。先进行了端口扫描，scan_port()函数

位于/nascan/lib/scan.py

def scan_port(self):
    try:
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        sock.connect((self.ip, self.port))
        time.sleep(0.2)
    except Exception, e:
        return
    try:
        self.banner = sock.recv(1024)
        sock.close()
        if len(self.banner) <= 2:
            self.banner = 'NULL'
    except Exception, e:
        self.banner = 'NULL'
    log.write('portscan', self.ip, self.port, None)
    banner = ''
    hostname = self.ip2hostname(self.ip)
    time_ = datetime.datetime.now()
    date_ = time_.strftime('%Y-%m-%d')
    try:
        banner = unicode(self.banner, errors='replace')
        if self.banner == 'NULL': banner = ''
        mongo.NA_INFO.insert({"ip": self.ip, "port": self.port, "hostname": hostname, "banner": banner, "time": time_})
        self.statistics[date_]['add'] += 1
    except:
        if banner:
            history_info = mongo.NA_INFO.find_and_modify(
                query={"ip": self.ip, "port": self.port, "banner": {"$ne": banner}}, remove=True)
            if history_info:
                mongo.NA_INFO.insert(
                    {"ip": self.ip, "port": self.port, "hostname": hostname, "banner": banner, "time": time_})
                self.statistics[date_]['update'] += 1
                del history_info["_id"]
                history_info['del_time'] = time_
                history_info['type'] = 'update'
                mongo.NA_HISTORY.insert(history_info)

通过socket连接，获得端口服务返回的banner信息，然后进入server_discern()函数，通过正则表达式，依次比较，获得服务类型。

server_discern()函数

位于/nascan/lib/scan.py

def server_discern(self):
    for mark_info in self.config_ini['Discern_server']: # 快速识别
        try:
            name, default_port, mode, reg = mark_info
            if mode == 'default':
                if int(default_port) == self.port:
                    self.server = name
            elif mode == 'banner':
                matchObj = re.search(reg, self.banner, re.I | re.M)
                if matchObj:
                    self.server = name
            if self.server:break
        except:
            continue
    if not self.server and self.port not in [80,443,8080]:
        for mark_info in self.config_ini['Discern_server']:  # 发包识别
            try:
                name, default_port, mode, reg = mark_info
                if mode not in ['default','banner']:
                    dis_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                    dis_sock.connect((self.ip, self.port))
                    mode = mode.decode('string_escape')
                    reg = reg.decode('string_escape')
                    dis_sock.send(mode)
                    time.sleep(0.3)
                    dis_recv = dis_sock.recv(1024)
                    matchObj = re.search(reg, dis_recv, re.I | re.M)
                    if matchObj:
                        self.server = name
                        break
            except:
                pass
    if self.server:
        log.write("server", self.ip, self.port, self.server)
        mongo.NA_INFO.update({"ip": self.ip, "port": self.port}, {"$set": {"server": self.server}})

对于没识别出来的服务类型，端口号又不是常见端口号，会重新发包,发送特定包才会返回应答banner的服务类型。

最后如果还没识别出来，进入try_web()函数

位于/nascan/lib/scan.py

def try_web(self):
    title_str, html = '', ''
    try:
        if self.port == 443:
            info = urllib2.urlopen("https://%s:%s" % (self.ip, self.port), timeout=self.timeout)
        else:
            info = urllib2.urlopen("http://%s:%s" % (self.ip, self.port), timeout=self.timeout)
        html = info.read()
        header = info.headers
    except urllib2.HTTPError, e:
        html = e.read()
        header = e.headers
    except:
        return
    if not header: return
    if 'Content-Encoding' in header and 'gzip' in header['Content-Encoding']:  # 解压gzip
        html_data = StringIO.StringIO(html)
        gz = gzip.GzipFile(fileobj=html_data)
        html = gz.read()
    try:
        html_code = self.get_code(header, html).strip()
        if html_code and len(html_code) < 12:
            html = html.decode(html_code).encode('utf-8')
    except: pass
    try:
        title = re.search(r'<title>(.*?)</title>', html, flags=re.I | re.M)
        if title: title_str = title.group(1)
    except: pass
    try:
        web_banner = str(header) + "\r\n\r\n" + html
        self.banner = web_banner
        history_info = mongo.NA_INFO.find_one({"ip": self.ip, "port": self.port})
        if 'server' not in history_info:
            tag = self.get_tag()
            web_info = {'title': title_str, 'tag': tag}
            return web_info
        else:
            if abs(len(history_info['banner'].encode('utf-8')) - len(web_banner)) > len(web_banner) / 60:
                del history_info['_id']
                history_info['del_time'] = datetime.datetime.now()
                mongo.NA_HISTORY.insert(history_info)
                tag = self.get_tag()
                web_info = {'title': title_str, 'tag': tag}
                date_ = datetime.datetime.now().strftime('%Y-%m-%d')
                self.statistics[date_]['update'] += 1
                log.write('info', None, 0, '%s:%s update web info'%(self.ip, self.port))
                return web_info
    except:
        return

def ip2hostname(self,ip):
    try:
        hostname = socket.gethostbyaddr(ip)[0]
        return hostname
    except:
        pass
    try:
        query_data = "\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x20\x43\x4b\x41\x41" + \
                     "\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41" + \
                     "\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x00\x00\x21\x00\x01"
        dport = 137
        _s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        _s.settimeout(3)
        _s.sendto(query_data, (ip, dport))
        x = _s.recvfrom(1024)
        tmp = x[0][57:]
        hostname = tmp.split("\x00", 2)[0].strip()
        hostname = hostname.split()[0]
        return hostname
    except:
        pass

def get_code(self, header, html):
    try:
        m = re.search(r'<meta.*?charset=(.*?)"(>| |/)', html, flags=re.I)
        if m: return m.group(1).replace('"', '')
    except:
        pass
    try:
        if 'Content-Type' in header:
            Content_Type = header['Content-Type']
            m = re.search(r'.*?charset=(.*?)(;|$)', Content_Type, flags=re.I)
            if m: return m.group(1)
    except:
        pass

这个函数就是尝试用web访问，如果有结果的话就保存下来，没有的话就不管了。

回到nascan。

大概每隔一分钟探测是否要进行扫描。

参考文章：

https://landgrey.me/xunfeng-nascan-analysis/

https://www.cnblogs.com/yangxiaodi/p/8011563.html