False Positive
Microsoft Defender wrongly flags DigiCert certs as Trojan:Win32/Cerdigent.A!dha
Microsoft Defender is detecting legitimate DigiCert root certificates as Trojan:Win32/Cerdigent.A!dha, resulting in widespread false-positive alerts, and in some cases, removing certificates from Windows. According to cybersecurity expert Florian Roth, the issue first appeared after Microsoft added the detections to a Defender signature update on April 30th. Today, administrators worldwide began reporting that DigiCert root certificate entries were flagged as malware and, on […]
Microsoft: Anti-phishing rules mistakenly blocked emails, Teams messages
Microsoft says an Exchange Online issue that mistakenly quarantined legitimate emails last week was triggered by faulty heuristic detection rules designed to block credential phishing campaigns. As Microsoft explains in a preliminary post-incident report published this week, a software error in its email security system incorrectly flagged thousands of legitimate URLs as phishing links for nearly a week, […]
Microsoft: Exchange Online flags legitimate emails as phishing
Microsoft is investigating an ongoing Exchange Online issue that mistakenly flags legitimate emails as phishing and quarantines them. The incident began on February 5 and continues to affect Exchange Online customers, preventing them from sending or receiving emails. “Some users’ legitimate email messages are being marked as phish and quarantined in Exchange Online,” Microsoft said in […]
Microsoft Teams to let users report messages wrongly flagged as threats
Microsoft says that Teams users will be able to report false-positive threat alerts triggered by messages incorrectly flagged as malicious. This new feature was first announced in September, when it entered a targeted rollout phase, and will roll out to users worldwide by the end of November 2025. “Microsoft Teams now enables users to report messages they […]
Microsoft Defender mistakenly flags SQL Server as end-of-life
Microsoft is working to resolve a known issue that causes its Defender for Endpoint enterprise endpoint security platform to incorrectly tag SQL Server software as end-of-life. According to a service alert seen by GeekFeed, this bug has been impacting Microsoft Defender XDR customers with SQL Server 2017 and 2019 since at least Wednesday morning. While Defender flagged […]
Microsoft Defender bug triggers erroneous BIOS update alerts
Microsoft is working to resolve a bug that causes Defender for Endpoint to incorrectly tag some devices’ BIOS (Basic Input/Output System) firmware as outdated, prompting users to update it. In a service alert seen by GeekFeed, Redmond said that this known issue affects Dell devices and is caused by a Defender for Endpoint logic bug. “Microsoft have identified […]
Microsoft: Anti-spam bug blocks links in Exchange Online, Teams
Microsoft is working to resolve a known issue that causes an anti-spam service to mistakenly block Exchange Online and Microsoft Teams users from opening URLs and quarantine some of their emails. In a service alert seen by GeekFeed, the company stated that the issue is caused by the anti-spam engine incorrectly tagging URLs contained within other URLs […]
Microsoft fixes Exchange Online bug flagging Gmail emails as spam
Microsoft has resolved an issue with a machine learning model that mistakenly flagged emails from Gmail accounts as spam in Exchange Online. Tracked as EX1064599 in the Microsoft 365 admin center, the issue started impacting users on April 25 at 09:24 UTC, automatically moving emails erroneously tagged as malicious to the junk folder. “We’ve identified that our […]
Microsoft fixes machine learning bug flagging Adobe emails as spam
Microsoft says it mitigated a known issue in one of its machine learning (ML) models that mistakenly flagged Adobe emails in Exchange Online as spam. As the company revealed in an advisory on the Microsoft 365 admin center tagged as EX1061430, users had issues accessing alerts for Adobe URLs starting April 22 at 09:24 UTC while […]
Microsoft: Exchange Online bug mistakenly quarantines user emails
Microsoft is investigating an Exchange Online bug causing anti-spam systems to mistakenly quarantine some users’ emails. According to a new incident report added to the Microsoft 365 Admin Center, the email issues started almost five hours ago, at 10:11 UTC. While the company has yet to share what regions are impacted, this Exchange Online incident has been tagged as a critical […]