Anti-Spyware - Rootkit Revealer
Rootkit Revealer - is an advanced root kit detection utility. It output lists Registry and file system API discrepancies that may indicate the presence of a user-mode or kernel-mode rootkit. RootkitRevealer successfully detects all persistent rootkits published at www.rootkit.com, including AFX, Vanquish and HackerDefender (note: RootkitRevealer is not intended to detect rootkits like Fu that don't attempt to hide their files or registry keys.