This post was written before McAfee wrongly identified svchost.exe as a virus and caused many large businesses to close their doors while the problem was resolved:

Fixing a laptop for a friend gratis Has some sort of malicious application known as "Security Tool" installed (under windows 7) into c:\programdata\81504826\81504826.exe

You would think that a Malware Application that installs itself into the RUN key with a random executable name and that shuts down cmd.exe and regedit.exe when you launch them would immediately be recognized by a so-called anti-virus anti-spam (10.15.106) suite such as McAfee version 9.15

No such joy. Right clicking and choosing to scan the file didn't pick it up.

So after a suggestion from a friend I installed MalwareBytes which currently is scanning and has found the problem.

So trusting in your antivirus vendor to get it right all the time may get you caught out.