Find out how they got in and make sure that hole is fixed.
Do an rpm verify on all installed packages (excluding configs), reinstall the rpms that fail the verify.
Find all binaries that are not accountable in rpm and nuke them.
Harden your host with selinux and audit, keep audit logs of all changes to binary files and essential configs and make sure the audit logs are immutable.
Keep an eye on the system for a while to make sure you haven't missed anything.
Keep LVM snapshots of your OS LVs.
-Ross
-----Original Message-----
From: centos-bounces@centos.org <centos-bounces@centos.org>
To: CentOS mailing list <centos@centos.org>
Sent: Thu Nov 29 17:43:44 2007
Subject: [CentOS] CleanLog.h
Sad to say one of my file servers was exploited and used to run a Phishing scam. Have identified subject virus amongst other things. It appears twice in a virus scan; /sbin/z (which I assume can just be deleted) and /sys/bus/serio/drivers/atkbd/description. The latter file is also present in identical uninfected machines. I have been unable to open the file, even with root privileges, although it appears to be a text file. Any suggestions on how to proceed appreciated. Guess I could delete it and copy over the file from an identical machine.
Thanks in advance,
B.J.
CentOS 5.0, Linux 2.6.18-8.1.15.el5 x86_64 16:26:48 up 10:46, 1 user, load average: 0.07, 0.08, 0.04