The most recent Windows patch, released April 9, seems to have done something (still to be determined) that’s causing problems with anti-malware software. Over the last few days, Microsoft has been adding more and more antivirus scanners to its list of known issues. As of publication time, client-side antivirus software from Sophos, Avira, ArcaBit, Avast, and most recently McAfee are all showing problems with the patch.
Affected machines seem to be fine until an attempt is made to log in, at which point the system grinds to a halt. It’s not immediately clear if systems are freezing altogether or just going extraordinarily slowly.
