Just fixed a computer with the Harbinger 'rootkit' virus.
Typical tools used to clean the computer, plus the Kaspersky bootkit removal tool called TDSSKiller Kaspersky webpage link.
If you do decide to download from other sources (when doing a Google search on TDSSKiller sometimes one get 3rd party mirrors, then download from CNET webpage
I tried downloading from some other sources, like It was interesting how it operated, it created audio soundtracks when a browser opened. The audio was from various sound files on the computer and from ads on the Internet. The virus ran in the background (not obvious it was running, but you could hear it). The rootkit likely ran and was doing its masters bidding.
The sound was odd advertisements, shows local to the area and other random noises. It was very odd, and of course annoying. After the Kaspersky tool ran (in safemode) then the system was clean.
Also remember to patch your machines, there are a lot of Microsoft vulnerabilities coming out soon.
Here is the Microsoft Techcenter Security Bulletin list: Microsoft webpage