[CentOS] Compromised

Wed Sep 10 03:47:15 UTC 2008
Jason Sutherland <jay at jaysweb.net>

Yeah pull the network plug first. Then boot up with a knoppix CD to 
backup your data and/or image the disk, then reload. I'm sure you could 
do a full audit of the system but reloading is likely much quicker.

A word to the wise on the account pcguest, if it was one you created, 
set the shell to something like /sbin/nologin. That can help to prevent 
unauthorized ssh access if you happen to leave a password blank. I'll 
leave the additional suggestions and heckles to others on the lists.

Miark wrote:
> My wife's office server was compromised today. It appears
> they ssh'ed in through account pcguest which was set up for
> Samba. (I don't remember setting up that account, but maybe I
> did.) At any rate, I found a bazillion "ftp_scanner" processes
> running. A killall finished them off quickly, I nuked the
> pcguest account, and switched ssh to a different port (which 
> I normally do anyway). 
>
> I used 'find' to locate ftp_scanner, which was running in a
> folder under /var/tmp. It seems that before I could nuke the
> directory, it nuked itself! 
>
> Because it was running from /var/tmp, and because 'find' and
> 'ps' were not compromised (in that they did not hide the
> ftp_scanner processes or files), I'm thinking the attacker 
> really didn't get any further than eating some bandwidth. 
>
> I suppose I have no choice but to re-install, but I thought I'd
> run I'd get some feedback first. (Something other than, "Way to
> go, moron.") In the meantime, I'm pulling the plug.
>
> Miark
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