ComboFix needs it’s own page as part of the spyware, adware, virus, malware, etc…. toolkit.
It’s been designed to automatically clean up a long list of known malware. One of my favorite features though is the quick ability to download and install the Windows Recovery Console “just in case”. Unfortunately, many PC’s don’t have the Windows Recovery Console installed out of the box and when a system is seriously infected it can be a handy option. In this case, it’s installed to assist if things go wrong with the cleanup.
Users are warned not to use combofix without reading instructions. It’s possible that combo fix will clean things up on the first pass, but the log file it generates can give useful clues on what may still be left to clean out. In many cases, people will have run combofix in response to a forum request that they run it and then report back the results. There is a list of support forums available at the instructions link above.