Google Ads Spread Fake Security Scams That Trap Users in Frozen Screens

Security researchers at Netskope have uncovered a sophisticated scam that weaponized Google Ads to deliver deceptive tech support schemes targeting Windows and Mac users. The malicious advertisements appeared across hundreds of legitimate websites—including maps, weather, real estate, document hosting, and sports portals—and triggered a fake security warning that appeared to lock users' screens.

How the Scam Works#

When users clicked on the malicious ads, their browsers displayed a full-screen warning claiming their device was infected. The fake security overlay would:

• Fill the entire screen with urgent warnings
• Hide the mouse cursor
• Block standard keyboard exit commands
• Deliberately slow the browser to simulate a compromised system

The psychological manipulation is key: nothing on the actual computer was locked or damaged, but the visual deception was convincing enough to pressure panicked users into calling the phone number displayed on screen. Those who made the call faced pressure to pay substantial fees, grant remote access to their machines, or share sensitive personal information.

Scale of the Campaign#

Between August 31 and September 14, Netskope's security monitoring detected clicks on the malicious ads from 619 customer organizations across 250+ distinct Google Ads campaign IDs. The campaigns targeted at least 284 legitimate publisher sites. Although Netskope's security filters protected its customers from being scammed, the firm estimates far broader exposure given that their visibility represents only a fraction of total web traffic.

The geographic distribution showed the US accounting for roughly 62 percent of affected organizations, followed by Japan and Australia. Netskope did not report any of its monitored users actually falling victim to the fraud, but this likely reflects only protected traffic.

Why These Scams Still Work#

Despite widespread public awareness campaigns and mockery of victims, these schemes continue to target a vulnerable population. Many Internet users lack fundamental understanding of how computers and browsers function. When combined with time pressure, stress, and the increasingly complicated experience of browsing the web, even cautious individuals can become susceptible. According to Netskope's analysis, "nothing on the computer is actually locked, but in the moment it is convincing enough to push people toward the scam."