FISA

Cybersecurity researchers have detailed an updated version of an advanced fingerprinting and redirection toolkit called  WoofLocker  that's engineered to conduct tech support scams. The sophisticated traffic redirection scheme was first documented by Malwarebytes in January 2020, leveraging JavaScript embedded in compromised websites to perform anti-bot and web traffic filtering checks to serve next-stage JavaScript that redirects users to a browser locker (aka browlock). This redirection mechanism, in turn, makes use of steganographic tricks to conceal the JavaScript code within a PNG image that's served only when the validation phase is successful. Should a user be detected as a bot or not interesting traffic, a decoy PNG file without the malicious code is delivered. WoofLocker is also known as 404Browlock due to the fact that visiting the browlock URL directly without the appropriate redirection or one-time session token results in a 404 error page. The cybersecur...