Microsoft fixes Windows zero-day exploited in ransomware attacks

Microsoft has fixed a zero-day bug which cyber attackers were using to sidestep its Windows SmartScreen anti-malware service and install Magniber ransomware. Google’s Threat Analysis Group revealed the exploit, which involved the use of malicious MSI files, signing them with fake signatures to avoid triggering security alerts. This allowed for over 100,000 downloads of the malicious files since January 2023, mainly in Europe. The bug stemmed originally from a narrow patch by Microsoft rather than a more comprehensive fix.