A new Windows zero-day allows threat actors to use malicious JavaScript files to bypass Mark-of-the-Web security warnings. Threat actors are already seen using the zero-day bug in ransomware attacks.

Attackers frequently send malicious JavaScript files through bogus emails. It's easy to block these files from reaching a hapless user. Here's how.

A recent malicious campaign delivering Magniber ransomware has been targeting Windows home users with fake security updates.

However, opening an unknown JS file on Windows can be dangerous, as it runs inside Windows Script Host by default. From there, the script can easily run Windows executables.