Combofix is a set of tools carefully coded to scan, detect, and remove malware, trojans, and toolbars. It's using advanced techniques to stop the spreading of bad content. It's like an antivirus built from multiple 3rd party tools.
However, the application is free. You can download it via the download page: http://www.combofix.org/download.php
Click on the **bleepingcomputer** link.