Among all of the free antivirus software we've tested recently, Panda Cloud Antivirus was the best app at blocking known malware.
However, Panda Cloud Antivirus's work-in-progress status and its unique methods kept us from ranking it on our free antivirus software chart.
Panda Cloud Antivirus is still in beta and not feature-complete. At this writing, it's easy enough to install and use, but Panda is still adding features, and some bugs (large or small) may remain. For example, during our testing, we ran into a performance glitch, but since then it seems to have been fixed.
Rather than using your PC's processing power, this cloud-based app sends data about potentially malicious files and programs to Panda's servers for analysis. The approach is intended to take advantage of the latest signatures without the need for signature-database updates - and if its excellent showing at detecting malware in AV-Test.org's zoo of half a million samples is any indication, the approach works. Panda Cloud Antivirus produced an impressive 99.4 percent overall detection rate.
However, Panda Cloud Antivirus's design also meant that it could not work with our current method of proactive-protection testing, which requires us to use two- and four-week-old signature databases to simulate how well an antivirus tool performs against new, unknown malware. The same goes for our on-access scan tests, which gauge how much slowdown a program introduces when it scans files that the user copies.
Panda uses a multitiered scanning model that only blocks access and does an immediate scan for programs that attempt to run, which it considers the highest risk. Files on a hard drive (preexisting and newly copied) are tagged for background scans only during idle time, to improve performance. (The app checks downloaded files right away, but doesn't block the files before the scan).
On a full on-demand scan, Panda Cloud Antivirus offered middling speed. It was reasonably good at cleaning existing malware, and it detected all ten test infections. But it failed to disable one infection, and it failed to remove Registry entries and other largely harmless junk after every cleanup attempt.
NEXT: our expert verdict >>