Malwarebytes (software)
Anti-Malware is, as its name suggests, an anti-malware program developed as shareware by Malwarebytes that detects and removes malware on a user's computer. It's primarily focused on combating trojans, browser hijackers, and other components more serious than spyware and less so than viruses, although it also detects some of these as well. It is Malwarebytes' central project.
Malwarebytes offers a free, downloadable version, which can be upgraded to the full paid version which protects against incoming malware and performs scheduled scans and updates.