A new study by OPSWAT suggests that free antivirus applications outrank paid versions in popularity among users. While not shocking, it's an interesting discovery considering the fact that most large system builders ship their machines with Symantec or McAfee preinstalled, leaving smaller companies to rely on after-market installs. It's unclear what percentage of the usage is consumers and how much is enterprise-based.

Avast Free is supposedly the most popular software, taking 11.45% of the pie. Avira AntiVir Personal follows with 9.19%, AVG Free has 8.6%, and Microsoft Security Essentials has carved out a handsome 7.48% since debuting late last year. Below the freebies is Avast (paid) with 5.4%, Kaspersky had 4.48%, Norton at 4.24%, and ESET NOD32 claimed 3.84%.

OPSWAT combined different version numbers for each application, but most vendors have a few separate products, which makes the antivirus software chart a bit confusing. That said, things don't change much when you look at vendors. Avast leads with 19.14%, Avira has 11.39%, Symantec takes 10.06%, Microsoft claims 9.29%, while AVG is just below that with 9%.

The research firm also graphed the location of antivirus vendors. Apparently, 52% of those in the study are European, including Avast, Avira, AVG, ESET, Panda, BitDefender, G Data and Sophos. Meanwhile, 31% are located in the US, including Symantec, Microsoft, McAfee, PC Tools and Sunbelt. Numbers aside, what's your preferred antivirus and why?