Aliases: Packed.Win32.PePatch.ca (Kaspersky), Generic.dx (McAfee), Downloader (Symantec), TR/PCK.PePatch.CA.2 (Avira), Mal/EncPk-BW (Sophos)
It attempts to drop a DLL component in the Windows system folder. It is also designed to download and execute files from a remote server. As a result, the routines of the downloaded files may be exhibited on the affected system.
Scan online and free removal:
Housecall:
http://housecall.trendmicro.com
Also scan online for free with ESET (requires Internet Explorer)
http://www.eset.com/onlinescan/index.php
Accept Terms of Use, Install ActiveX, click Start and tick both boxes, Remove found threats and Scan unwanted applications.
This can take a while to run, so just leave it to scan and remove infections.