3Nov/111
Scan your server for rootkits with rkhunter
rkhunter (Rootkit Hunter) is a tool that scans for rootkits, backdoors and possible local exploits. It does this by comparing SHA-1 hashes of important files with known good ones in online database, searching for default directories (of rootkits), wrong permissions, hidden files, suspicious strings in kernel modules, and special tests for Linux and FreeBSD.
1. Install rkhunter
apt-get install rkhunter