a-squared (a²) is a complementary product to antivirus software which is specialized in protection against harmful software. Antivirus software often features an inadequate protection against Trojans, Dialers and Spyware. a² fills this gap.

a² is free, however you can purchase the "Personal Edition" for $29.95 which includes more advanced features such as:
- Intrusion Detection System
- Analyses the behavior of all running programs
- System-Firewall
- Autostart-Viewer
- Process-Viewer
- Automatic update

This program contains only the scanner, but no background guard. The personal edition adds that and more for $39.95