Security firm Netskope reports that Google ads have been delivering a convincing tech support scam that freezes browsers on both Windows and Mac devices. The ads appeared across high-traffic sites like maps, weather, and real-estate pages, and displayed full-screen warnings urging users to call a bogus call center. From August 31 to September 14, Netskope observed clicks from 619 customer organizations, though none were scammed because the firm blocked the content. Since Netskope only sees a small slice of internet activity, the true scale of exposure is likely much larger.
The scam uses encrypted code that only activates after a mouse movement, making it hard for security tools and Google's ad filters to detect. It mimics a real infection by hiding the cursor, disabling exit keys, and degrading browser performance. However, the device is not actually locked. Users can usually escape by holding the escape key for several seconds, or by using the Windows Task Manager (control-shift-escape) or Mac's force-quit menu (cmd-option-escape).
Google said it has "zero tolerance for scams" and is investigating the campaigns, but did not explain why its scanners missed them. The report highlights that many users lack the technical knowledge to recognize such tricks, and that ridicule from more savvy users ignores how convincing these scams can be. No legitimate company will ever ask you to call a number for a virus warning, so the safest response is to close the browser without calling.