Comodo is and foremost a Firewall with HIPS. Its is not a virus scanner or malware scanner. The scanner built into Comodo is a new feature and mainly used upon first installs to be sure your pc is clean. But do not rely on it. If you want a good spyware scanner use Spybot and SuperAntiSpyware. If you want a good anti virus use NOD32,Kaspersky,Avira AntiVir,Dr. Web. Good free anti viruses are AVG and Avast.
Hi Cold Achilles, Oriour was correct in stating that the firewall is primarily a firewall and HIPS for your computer. The scanner built into it was and still is primarily a dry run for the on demand scanner to be built into the third incarnation of Comodos Antivirus. As to whether it gets updated regularly I can only hazard a guess.