A-Squared Anti-Malware is the paid version and has real-time protection, automatic updates and schedule scans. A-Squared Free like the paid version scans for and removes infections of trojans, viruses, spyware, adware, worms, bots, keyloggers and dialers, but lacks the automatic updates, real-time protection and schedule scans of the paid version. Both versions use the a-squared Anti-Spyware, and the Ikarus Anti-Virus engine.