Because of the way Threatfire works, we were unable to test it against our malware zoo of known threats. Threatfire doesn't use traditional signature files; instead, it relies solely on behavioral analysis—that is, it identifies malware based on how the invader acts on your PC.
That technology should make Threatfire fantastic at ferreting out new malware, and our tests bear that out. The tool produced outstanding results when blocking malware in our real-world tests: It fully blocked 92.9% of malware, and partially blocked the remaining 7.1%, the best showing of any free antivirus app we looked at this year.
As mentioned, Threatfire falters at disinfection: It detected and disabled only about half of the infections on our test PC. Because of this, it's best to install Threatfire on a clean, malware-free system.
Threatfire is designed to work side by side with most antivirus products, so if you just bought a new PC, installing Threatfire is a good addition to your setup routine.Malwarebytes' Antimalware
Malwarebytes' Antimalware is another supplemental free product that can help bolster your existing security software. The makers of Malwarebytes' Antimalware pitch it as a tool for detecting and removing brand-new "zero-day" malware, and it uses a number of different technologies to accomplish this task.
The software did perform decently compared with other freebies when it came to stopping new malware. In our real-world tests, Malwarebytes fully blocked 78.6% of samples—slightly better than average—and partially blocked an additional 14.3%. It's also reasonably fast: It had the lightest overall impact on system performance of any free antivirus product we tested.
Malwarebytes isn't something you'll want to use as your primary antivirus software, though, as it isn't great at stopping known malware: It detected a scant 57.1% of known malware samples collected from the past four months—far and away the worst result we saw from any of the freebies tested.
The software has a fairly no-frills interface, but it's straightforward. One clever feature is Chameleon, which lets the program run even when a particularly evil piece of malware attempts to block it.
Malwarebytes' makers don't see its product as a first line of antivirus defense, and frankly, neither should you. But it's something to consider adding to your security toolbox.
Hands On With Ad-Aware 10
Ad-Aware recently released version 10 of its free antimalware software. The program came in too late for our full suite of testing, but we had a look at its slick new user interface.