This is the offcial description of ComboFix. You can found the originial here.
ComboFix is a program, created by sUBs, that scans your computer for known malware, and when found, attempts to clean these infections automatically. In addition to being able to remove a large amount of the most common and current malware, ComboFix also displays a report that can be used by trained helpers to remove malware that is not automatically removed by the program.
Please note that running this program without supervision can cause your computer to not operate correctly. Therefore only run this program at the request of an experienced helper.
This program works with Windows 8, but not Windows 8.1 and Windows 10 at this time!