We’ve tackled about fake tech support helpers in the past, pretending to fix PCs in exchange for either a fee or a victim’s credit card information. Now a certain exploit that Google Chrome already fixed last February has resurfaced – scammers trying to scare victims by making their browsers unresponsive.
These scammers abuse a particular browser programming interface called window.navigator.msSaveOrOpenBlob. It’s responsible for saving browser files locally through web storage. What they then do is combine this feature with other browser functions, which when done right, forces the web to save files locally without stopping in an infinite loop, and with intervals so fast the victim’s browser will freeze and will remain unquittable.
To put the victim into a more panicked state, the scammers made sure to display a scary red-font message before the browser completely freezes. It states that your Internet Service Provider has blocked your PC, and that it is critical to contact Microsoft immediately, with the corresponding technical support number posted all in red text.
Needless to say, the posted technical support number is fake. A seemingly legitimate Microsoft technical employee will answer the call and asks for credit card information before fixing the issue. Testimonies often suggest these scammers originating in India, but it could very well be from another country.
Moreover, a recent Mozilla developer forum reported a similar case, suggesting that the problem isn’t only limited to Google Chrome. Users are advised to stay alert whatever web browser they’re using.
Outsmarting the Scammers
It is important not to panic and not to comply when looking at technical support scams, and definitely not calling the fake number they’ve provided. If you really need to call Microsoft, then visit their official website and get the real number their.
During a browser freeze, it is best practice to let Windows Task Manager or macOS Force Quit feature kill the unresponsive task for you.