Millions of Chrome Users Have Installed Malware Posing as Ad Blockers

Kaleigh Rogers, writing for Motherboard: Andrey Meshkov, the cofounder of ad-blocker AdGuard, recently got curious about the number of knock-off ad blocking extensions available for Google's popular browser Chrome. These extensions were deliberately styled to look like legitimate, well-known ad blockers, but Meshkov wondered why they existed at all, so he downloaded one and took a look at the code. "Basically I downloaded it and checked what requests the extension was making," Meshkov told me over the phone. "Some strange requests caught my attention." Meshkov discovered that the AdRemover extension for Chrome -- which had over 10 million users -- had code hidden inside an image that was loaded from the remote command server, giving the extension creator the ability to change its functions without updating. This alone is against Google's policy, and after Meshkov wrote about a few examples on AdGuard's blog, many of which had millions of downloads, Chrome removed the extensions from the store. I reached out to Google, and a spokesperson confirmed that these extensions had been removed.