Removing rootkits without compromising system integrity is particularly challenging and needs to be done with care. Our free software, Sophos Anti-Rootkit, finds and removes any rootkit that is hidden on your computer.
Thanks for report about this. I just tried now it after read this post.
Sophos are cool, they provide MD5 checksum, seems they serious about security.
It is a 1,07 mb file download. Seems to be a self-extracting RAR file. You extract it to a location of your choice, then run sargui.exe, it will then scan running processes, Windows registry and local hard drives.
It's pretty cool and a fast scanner at that, it only needs an update button that will auto download and install the newest version. They claim it doesn't write to the registry in one of the help files, but it does write an entry to an non-existing .dll file for "Windows\System32".