I originally found this on Lazy Genius.
“The idea behind SVV is to check important Windows System components, which are usually altered by various stealth malware, in order to ensure system integrity and to discovery potential system compromise.”
She has other tools on her download page.
Note: This is a technical tool intended for an advanced user. If you’re just getting in to rootkits, I would start with the Sysinternals Rootkit Revealer.