Con artists pushing tech-support scams are once again exploiting a Chrome bug that can give users the false impression they’re experiencing a serious operating-system error that requires the urgent help of a paid professional, according to a Google developer forum. A Mozilla developer forum indicates a similar bug may also be present in Firefox.
The scam technique, which came to light in February, works by abusing the programming interface known as the window.navigator.msSaveOrOpenBlob. By combining the API with other functions, the scammers force the browser to save a file to disk, over and over, at intervals so fast it’s impossible for normal users to see what’s happening.