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Unfriendly crontab additions

Published: 2013-12-24
Last Updated: 2013-12-24 13:22:26 UTC
by Daniel Wesemann (Version: 1)
9 comment(s)

SANS ISC reader Christopher found the following in the crontab of a customer's CentOS machine. I include it as an image here, to keep your anti-virus from panicking on this diary six months from now ...

Roughly every 90 minutes, this crontab will download and start the latest version of a backdoor / DDoS trojan off the dgnfd564sdf website. Every minute, it will also turn off the firewall if one is running (iptables stop) and try and hide its presence (history -c,  >.bash_history, etc). Current assumption is that the bad guys got in via an unknown webmin vulnerability or - most likely - via a weak password. We're still investigating the binaries:

5d10bcb15bedb4b94092c4c2e4d245b6  atdd
0d79802eeae43459ef0f6f809ef74ecc  cupsdd
9a77f1ad125cf34858be5e438b3f0247  ksapd
9a77f1ad125cf34858be5e438b3f0247  sksapd
a89c089b8d020034392536d66851b939  kysapd
a5b9270a317c9ef0beda992183717b33  skysapd

All six are >1.2mb and of type "ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, for GNU/Linux 2.2.5, not stripped". The wget links are currently still live, investigate at your own risk.

If you have seen the same thing or additional insights, please share in the comments below!

 

9 comment(s)
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