How to implement CentOS to continuously send out packages
如何实现CentOS不停向外发包?
服务器不停的向外发包,且CPU持续100%,远程登录后查看发现有一长度为10的随机字符串进程,kill掉,会重新生成另外长度为10的字符串进程。删除文件也会重复生成,非常痛苦。查阅crond相关日志,发现实际执行的内容为/lib/libudev.so ,以此为关键字进行查询,找到如下内容:
1.1 工具/原料
Linux系统病毒文件libudev.so
1.2 方法/步骤
1.网络流量暴增,使用 top 观察有至少一個 10 个随机字母組成的程序執行,佔用大量 CPU 使用率。刪除這些程序,馬上又产生新的程序。
2.检查 cat /etc/crontab
发现定时任务 每三分钟执行一个脚本gcc.sh
*/3 * * * * root /etc/cron.hourly/gcc.sh
查看病毒程式 gcc.sh,可以看到病毒本体是 /lib/libudev.so。
[root@deyu ~]# cat /etc/cron.hourly/gcc.sh #!/bin/sh PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:/usr/X11R6/bin for i in `cat /proc/net/dev|grep :|awk -F: {'print $1'}`; do ifconfig $i up& done cp /lib/libudev.so /lib/libudev.so.6 /lib/libudev.so.6
刪除上一行例行工作 gcc.sh
,并设定 /etc/crontab无法变动,否则马上又会产生新的文件。
[root@deyu ~]# rm -f /etc/cron.hourly/gcc.sh && chattr +i /etc/crontab
使用 top 查看病毒為 mtyxkeaofa,id 为 16621,不要直接杀掉程序,否则会再次产生新的文件,而是停止其运行。
[root@deyu ~]# kill -STOP 16621
刪除 /etc/init.d 內的档案。
[root@deyu ~]# find /etc -name '*mtyxkeaofa*' | xargs rm -f
刪除 /usr/bin 內的档案。
[root@deyu ~]# rm -f /usr/bin/mtyxkeaofa
查看 /usr/bin 最近变动的档案,如果是病毒也一併刪除,其他可疑的目錄也一樣。
[root@deyu ~]# ls -lt /usr/bin | head
現在杀掉病毒程序,就不會再产生。
[root@deyu ~]# pkill mtyxkeaofa
刪除病毒本体。
[root@deyu ~]# rm -f /lib/libudev.so
使用此方法 可以完全清除此病毒。
1.3 注意事项
/proc里面的东西是可以更改的;lsof还比较忠诚,不直接读取/proc里面的信息,ps看到的就不一定真实,top看到的进程还是正确的。 附:find -o参数就是逻辑运算的or
相关参考:centOS教程
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