linuxubuntuamazon-ec2malware

kdevtmpfsi using the entire CPU

We are using an EC2(Ubuntu) amazon instance for running Apache.Recently we noticed that there is a process using the entire CPU.

enter image description here

We removed it using the help of the following procedure

[root@hadoop002 tmp]# systemctl status 25177
● session-5772.scope - Session 5772 of user root
   Loaded: loaded (/run/systemd/system/session-5772.scope; static; vendor preset: disabled)
  Drop-In: /run/systemd/system/session-5772.scope.d
           └─50-After-systemd-logind\x2eservice.conf, 50-After-systemd-user-sessions\x2eservice.conf, 50-Description.conf, 50-SendSIGHUP.conf, 50-Slice.conf, 50-TasksMax.conf
   Active: active (abandoned) since Wed 2020-01-22 16:06:01 CST; 1h 21min ago
   CGroup: /user.slice/user-0.slice/session-5772.scope
           ├─19331 /var/tmp/kinsing
           └─25177 /tmp/kdevtmpfsi

Jan 22 16:06:17 hadoop002 crontab[19353]: (root) REPLACE (root)
Jan 22 16:06:17 hadoop002 crontab[19354]: (root) LIST (root)
Jan 22 16:06:17 hadoop002 crontab[19366]: (root) LIST (root)
Jan 22 16:06:17 hadoop002 crontab[19374]: (root) REPLACE (root)
Jan 22 16:06:17 hadoop002 crontab[19375]: (root) LIST (root)
Jan 22 16:06:17 hadoop002 crontab[19383]: (root) REPLACE (root)
Jan 22 16:06:17 hadoop002 crontab[19389]: (root) REPLACE (root)
Jan 22 16:06:17 hadoop002 crontab[19390]: (root) LIST (root)
Jan 22 16:06:17 hadoop002 crontab[19392]: (root) REPLACE (root)
Jan 22 16:06:17 hadoop002 crontab[19393]: (root) LIST (root)
[root@hadoop002 tmp]# ps -ef|grep kinsing
root     19331     1  0 16:06 ?        00:00:04 /var/tmp/kinsing
root     25190 23274  0 17:27 pts/0    00:00:00 grep --color=auto kinsing
[root@hadoop002 tmp]# ps -ef|grep kdevtmpfsi
root     25177     1 99 17:27 ?        00:01:47 /tmp/kdevtmpfsi
root     25197 23274  0 17:28 pts/0    00:00:00 grep --color=auto kdevtmpfsi
[root@hadoop002 tmp]# kill -9 19331
[root@hadoop002 tmp]# kill -9 25177
[root@hadoop002 tmp]# rm -rf kdevtmpfsi
[root@hadoop002 tmp]# cd /var/tmp/
[root@hadoop002 tmp]# ll
total 16692
-rw-r--r-- 1 root root        0 Jan 13 19:45 aliyun_assist_update.lock
-rwxr-xr-x 1 root root    13176 Dec 20 02:14 for
-rwxr-xr-x 1 root root 17072128 Jan 19 17:43 kinsing
drwx------ 3 root root     4096 Jan 13 19:50 systemd-private-f3342ea6023044bda27f0261d2582ea3-chronyd.service-O7aPIg
[root@hadoop002 tmp]# rm -rf kinsing

But after a few minutes, It again started automatically. Anyone know how to fix this?

Solution

  • The solution mentioned here worked for us. You basically create the files the miner uses, without any rights, so the miner cannot create and use them. https://github.com/docker-library/redis/issues/217

    touch /tmp/kdevtmpfsi && touch /var/tmp/kinsing

echo "everything is good here" > /tmp/kdevtmpfsi

echo "everything is good here" > /var/tmp/kinsing

touch /tmp/zzz

echo "everything is good here" > /tmp/zzz

chmod go-rwx /var/tmp

chmod 1777 /tmp