A free VPN app called Big Mama is selling access to people's home internet networks. Kids are using it to cheat in a VR game while researchers warn of bigger security risks.

In the hit virtual reality game Gorilla Tag, you swing your arms to pull your primate character around -- clambering through virtual worlds, climbing up trees and, above all, trying to avoid an infectious mob of other gamers. If you're caught, you join the horde. However, some kids playing the game claim to have found a way to cheat and easily "tag" opponents.

Over the past year, teenagers have produced video tutorials showing how to side-load a virtual private network (VPN) onto Meta's virtual reality headsets and use the location-changing technology to get ahead in the game. Using a VPN, according to the tutorials, introduces a delay that makes it easier to sneak up and tag other players.

While the workaround is likely to be an annoying but relatively harmless bit of in-game cheating, there's a catch. The free VPN app that the video tutorials point to, Big Mama VPN, is also selling access to its users' home internet connections -- with buyers essentially piggybacking on the VR headset's IP address to hide their own online activity.

This technique of rerouting traffic, which is best known as a residential proxy and more commonly happens through phones, has become increasingly popular with cybercriminals who use proxy networks to conduct cyberattacks and use botnets. While the Big Mama VPN works as it is supposed to, the company's associated proxy services have been heavily touted on cybercrime forums and publicly linked to at least one cyberattack.

Researchers at cybersecurity company Trend Micro first spotted Meta's VR headsets appearing in its threat intelligence residential proxy data earlier this year, before tracking down that teenagers were using Big Mama to play Gorilla Tag. An unpublished analysis that Trend Micro shared with WIRED says its data shows that the VR headsets were the third most popular devices using the Big Mama VPN app, after devices from Samsung and Xiaomi.

"If you've downloaded it, there's a very high likelihood that your device is for sale in the marketplace for Big Mama," says Stephen Hilt, a senior threat researcher at Trend Micro. Hilt says that while Big Mama VPN may be being used because it is free, doesn't require users to create an account, and apparently doesn't have any data limits, security researchers have long warned that using free VPNs can open people up to privacy and security risks.