I just got infected and infested with a jcs.drivertickets.net ad window which appeared in a new browser window depending on where I clicked in the current window.

It seemed harmless (I just dismissed it) but it bothered me that nothing could find it.

I tried GMER, MBAR, MBAM, adwcleaner, spybot, hijackthis and superantispyware and got nothing. It also defeats MS RootkitRevealer.exe, the file won't even run.

After a Boot-Time Scan, Avast! finally found 'an extension added to Chrome' that enabled evil.

Removing the extension fixed the problem.