by   November 15, 2011 C/Net

Android owners relying on free antivirus apps may be headed for trouble.

Testing seven different free antivirus scanners for Android(PDF), AV-Test found most of them unreliable and unable to provide sufficient protection, especially in comparison to paid commercial apps.

Setting up its testbed, AV-Test ran the apps through their paces on a Samsung Galaxy Tab running Android 2.2.1.

The products tested were all downloaded from Google’s Android Market and included Antivirus Free from Creative Apps, BluePoint Antivirus Free from BluePoint Security, GuardX Antivirus from Qstar, Kinetoo Malware Scan from CPU Media SARL, LabMSF Antivirus beta from LabMSF, Privateer Lite from Online Vault, and Zoner AntiVirus Free from Zoner. To gauge their performance alongside commercial apps, AV-Test also looked at F-Secure’s Mobile Security and Kaspersky Mobile Security.

All the products were tested on their ability to perform on-demand scanning, as well as automatically detect malware that tries to install itself.

Among the free scanners, Zoner AntiVirus Free came out on top in the on-demand scan test, even though it detected only 32 percent of the malware on the tablet. Most of the other products found only 10 percent of the malicious files, while some didn’t detect any of the malware at all. In comparison, the apps from F-Secure and Kaspersky discovered at least 50 percent of the malware samples.

Most of the apps fared even worse at automatically detecting malicious software.

Zoner AntiVirus Free again took top place, detecting 8 out of the 10 malicious apps that tried to install themselves. BluePoint AntiVirus Free, Kinetoo Malware Scan, and Privateer Lite caught one malicious app, while Antivirus Free, GuardX Antivirus, and LabMSF Antivirus beta failed to detect any. Again, in comparison, F-Secure and Kaspersky found all 10 of the malware threats.

“The results of the real-time guard functionality were quite shocking,” AV-Test said in its report. The testing firm said it specifically chose 10 well-known malware samples that should’ve been picked up by any reliable virus scanner.

“The number of installations, which is given on the market Web site, shows that many users trust these free apps, although they do not offer a reliable protection,” AV-Test said. “The circulation of obviously near-to-useless security apps endangers those who trust them and install apps from third-party app markets without further suspiciousness.”

The results don’t provide a complete picture, according to MSNBC, since AV-Test failed to include other notable free Android AV apps, including AVG Antivirus Free, BitDefender Mobile Security, Lookout Mobile Security, and Norton Mobile Security.

But the study still serves as a call for Android users to carefully review any free AV product before installing it, to make sure it’s worth the effort.