Comodo Internet Security Premium 5.9 has an accessible interface, and it comes with a firewall. It's the only freebie we tested in our April 2012 free antivirus roundup that has a firewall, but in both malware blocking and cleanup, it ranks behind other free antivirus products we tested. Since this testing was completed, Comodo has released version 5.10, which has not yet been tested.
Comodo's performance in our real-world tests was acceptable: It blocked 78.6 percent of new malware, slightly above average compared with other free antivirus programs. It partly blocked an additional 21.4 percent of attacks. But Comodo protected poorly against well-known malware. It detected 98.2 percent of zoo samples. Though that may sound like a good score, only two of the nine products we tested performed worse.
Malware cleanup may be Comodo's Achilles' heel: It detected all infections, but it was successful in disabling malware only 80 percent of the time--quite low compared with the top performers. It left behind more malware remnants than any other product, too; it was successful in removing all traces of malware only a third of the time.
For the most part, Comodo had a light impact on PC performance, but it significantly slowed copying of files across the network. Comodo also took its time in scanning files for threats: Its on-demand scanner took 4 minutes, 31 seconds--the third-slowest result. Meanwhile, the on-access scanner required a staggering 13 minutes, 58 seconds to run, nearly twice as long as the next-slowest product. Although its included firewall makes Comodo Internet Security Premium appear attractive, we'd suggest giving other freebies a look first.