Note: This review addresses version 4.5 of the
Unlike most of the other pieces of free
antivirus software that we tested recently, PC Tools Threatfire
is not a stand-alone antivirus program. Instead, Threatfire
supplements your existing security app with highly effective
behavioral analysis that can stop malware based solely on what the
file tries to do on your PC.
Behavioral detection attempts to thwart the successful hacker
tactic of churning out ever greater numbers of malware variants to
stay one step ahead of traditional antivirus signature databases
(which the majority of security programs use). Other programs
employ behavioral or heuristic techniques, too (the latter looks
for partial matches with known malware). But behavioral detection
like the approach that PC Tools has implemented here can be
particularly tricky, as it’s prone to accidentally flagging
In AV-Test.org’s behavioral-detection tests, most apps have only
about a 30 percent to 60 percent detection rate. Not so for
Threatfire: It warned about every single one of the 15 malware
samples used, and it blocked all but one of them. What’s more, this
nimble malware nabber didn’t put up any false-positive warnings.
It’s hard not to be impressed with such stellar performance.
While running more than one regular antivirus app at the same
time can cause major problems, Threatfire should run smoothly
alongside existing security tools, including any of the free antivirus
software we ranked for our recent story. Since it detects only
programs that attempt to run, you’ll still want a standard
antivirus program to perform regular scans and to check files that
write to your hard drive, before they get a chance to execute.
Threatfire is simple to use and defaults to an appropriate
medium level of sensitivity, but we suggest turning on the option
in Settings, Quarantine to create a system restore point
automatically before quarantining anything. As for extras, a nice
system-activity monitor provides extensive technical details about
all currently running programs, and a mostly just-for-show threat
monitor maps global malware outbreaks.
Though Threatfire is designed to run with other apps, and we had
no problems in our tests, it has conflicted with AVG in the past.
That aside, we recommend Threatfire as a strong extra layer of