Windows users and system administrators worldwide are complaining that application shortcuts have disappeared from Start menus, desktops, and taskbars.
Unhappy sysadmins have taken to online forums like Reddit to discuss the issue.
The problem appears to be related to a malfunctioning attack surface reduction (ASR) rule issued with Windows Defender security intelligence update 1.381.2140.0 on Friday, 13 January 2023.
Administrators believe “Block Win32 API calls from Office Macro” is the offending ASR rule.
Mitigating the issue until Microsoft releases a fix will reportedly be laborious.
“The fix to #ASRmageddon is disable the ASR rules across the org and then (lol) recreate all the user shortcuts on all the machines somehow,” security researcher Kevin Beaumont said.
“Good luck and happy Friday the 13th.”
Microsoft issued a brief statement about the issue on Friday.
“We’re investigating an issue where users are unable to access application shortcuts on the Start menu and Taskbar in Windows,” said Microsoft.
“For more details and updates, please follow the SI MO497128 in your admin center.”
Microsoft has provided the following quick update in the admin center:
“We’ve identified that a specific rule was resulting in impact. We’ve reverted the rule to prevent further impact whilst we investigate further.”
Thanks to the sysadmin who sent us screenshots of the Microsoft 365 admin center.