Home windows directors from quite a few organizations report widespread account lockouts triggered by false positives within the rollout of a brand new Microsoft Entra ID’s “leaked credentials” detection app known as MACE.
These alerts and lockouts started final evening, with some admins believing they have been false positives because the accounts have distinctive passwords that aren’t used on another websites or functions.
Microsoft Entra ID, previously Azure Energetic Listing, is a cloud-based id and entry administration service that helps organizations handle consumer identities and safe entry to assets.
In a Reddit thread posted early this morning, Home windows admins reported receiving a number of alerts from Entra indicating that a few of their consumer accounts had been discovered with credentials leaked on the darkish internet or different places.
These accounts have been routinely locked out of the tenant, with quite a few customers impacted per group.
“Us as effectively… about 1/third of our accounts bought locked out about ~1 hour in the past. We’re a MSP so I am assuming that is taking place to our purchasers as effectively,” posted an admin on Reddit.
The locked-out accounts confirmed no indicators of compromise, equivalent to suspicious sign-ins, and have been protected with MFA. Moreover, breach notification providers like Have I Been Pwned (HIBP) had no matches for these accounts.
One other report on Reddit additional corroborated that this was widespread, with an MDR supplier stating they obtained over 20,000 notifications from Microsoft in a single day relating to leaked credentials from completely different clients
Whereas Microsoft has not publicly confirmed the reason for these lockouts, Microsoft informed one of many affected organizations it was brought on by a problem with the rollout of a brand new Enterprise software known as “MACE Credential Revocation.”
“Simply bought off with engineer. It’s Tenant Lockout on account of this MACE ninja rollout they did. no indicators of compromise. He wants an hour to transform the ticket from compromise to lockout however can breathe a sigh of reduction. It was Error Code: 53003 for conditional entry coverage,” an admin reported on Reddit.
A number of individuals confirmed this software was added to tenants proper earlier than they started receiving the alerts.
MACE Credential Revocation app is a Microsoft Entra characteristic used to detect leaked credentials and lockout doubtlessly compromised accounts.
Whereas all alerts of leaked credentials must be investigated to substantiate that an account was not compromised, should you obtained a flurry of alerts without delay this rollout probably brought about it.
BleepingComputer contacted Microsoft with questions on this incident however has not obtained a response presently.