In what could be regarded as a controversial test of anti-malware effectiveness, the influential Consumer Reports publication in its June issue gives its main recommendation to anti-malware freeware for protecting Windows and Mac computers. With some caveats, Consumer Reports says in its "Security Software" article it regards it as unnecessary to buy commercial anti-malware software.Consumer Reports says it carried out the testing of 18 separate anti-malware software applications -- four of them free and 14 paid -- in conjunction with International Consumer Research & Testing based on how well the software defended against live exploits from websites.MORE: Free antivirus programs rise in popularity, survey showsIt combined these results with other tests related to "ease of use," as well as a measurement of how the software used memory or other "resources" that might slow computer operation during a scan. The testing also looked at "scan speed" related to how fast large groups of files could be scanned, and "updating" to see how fast each software package would be updated against new malware. Other categories such as "information help," related to how clear and useful instructions are, and "clear warnings" were examined. The effectiveness of any "firewall performance," "spam filter," "parental filter" and "non-boot rescue" were also technically reviewed by Consumer Reports and its testing partner.In the June issue, Consumer Reports recommends that consumers use free anti-malware tools -- the top choice being Avira Free Antivirus, followed by AVG Anti-Virus Free 2012, Avast Free Antivirus and Microsoft Security Essentials, unless the user should be considered among the "most at-risk Internet users."However, the publication does not define what that is in much detail, except to suggest "if you remotely access files on your computer when you're away from home, for example, you'll need stronger protection."Consumer Reports also acknowledges "pay suites offer more features and are simpler to use, with a single interface, just one download and installation, and a single upgrade from time to time."Despite its strong recommendation for Avira and the three other anti-malware freeware programs, the Consumer Reports article indicates that the freeware it tested did not generally do better in the "Net threats" protection tests against viruses and exploits than the paid anti-malware software did. In fact, it usually did worse.In the "Net threats" dense tests against live exploits from websites, Avira Free Antivirus, Avast Free Antivirus and Microsoft Security Essentials earned the middle-tier "good" rating, with only AVG Anti-Virus Free 2012 rising above that to a "very good" ranking.In contrast, the paid Avira Internet Security 2012 did better against "Net threats" with a "very good" ranking, as did paid software from G Data Internet Security 2012, ESET Smart Security 5, Norton Internet Security 2012, F-Secure Internet Security 2012, BullGuard Internet Security 2012, and Trend Micro Titanium Internet Security 2012.Top-ranked for "Net threats" defense with an "excellent" rating were Kaspersky Internet Security 2012 and BitDefender Internet Security 2012. However, McAfee Internet Security 2012 and Panda Internet Security 2012, both paid anti-malware programs, only reached the middle-tier "good" category, according to the Consumer Reports "Net threats" tests.Ellen Messmer is senior editor at Network World, an IDG publication and website, where she covers news and technology trends related to information security.Read more about wide area network in Network World's Wide Area Network section.