I just took a look at Malwarebytes Anti-Malware, and it's a worthwhile security application. Some users and reviewers even think it's the best free malicious-software-only engine out there, and it's true that it has a lot going for it.
Surprisingly effective, it's a relatively speedy malicious software remover, with the quick scan taking about 10 minutes. The heuristics engine proved on multiple computers during empirical testing that it was capable of determining the difference between false positives and threatening dangers.
Notably, Malwarebytes was one of the few malicious software removal tools that proved useful to many people in removing the Antivirus XP 2008 spyware.
The application has some nice features rolled in, too. It supports multiple drive scanning, context menu options including a scan-on-demand for individual files, and the FileAssassin option under the More Tools section for removing locked files. Testing them engendered no problems. Single-serving size file testing saw the program load fast, although I wasn't able to test the FileAssassin because I lacked a locked file.
The interface is simple, but pleasant-looking and well organized. Tabs live just below the oversized logo, with few options per tab to keep down the clutter. The installation process was fast enough, even with an instant definition file update. It interestingly offered a well-maintained change log, which was informative if not overly useful.
Like many programs these days, the freeware version can be upgraded for a fee to include more features. In this case, the $24.95 price gets you a lifelong access code to turn on real-time protection and a scheduler for updates and scans. If Malwarebytes is used as a strong second to your rolled-into-one antivirus and malicious software removal engine such as Antivir or AVG, you probably won't miss much from the paid edition. Overall, Malwarebytes Anti-Malware is a responsive malicious software remover that does what it should with a minimum of fuss.