Threat Intelligence & APT BleepingComputer 1 month ago

Microsoft says some users can’t open the Teams desktop client

CN
CyberNew Threat Research Desk
• Original Reporting: BleepingComputer
CyberNew Threat Intel Assessment
Assessed Severity: INFORMATIONAL
Impacted Surface
Client Endpoints & Operating Systems
Intelligence Sector
Threat Intelligence & APT

Analyst Takeaway

"Microsoft is working to resolve a known issue that causes delays or blocks some users from opening the Microsoft Teams desktop client on Windows systems. The company acknowledged this known issue (tracked as TM1466820 ) at 16:45 EDT on Thursday and advised affected customers to work around it by using the web or mobile platforms. "Specifically, when first opening Microsoft Teams on Windows..."

Recommended Defense & Mitigation

  • Threat Monitoring: Ingest published IOCs into SIEM/EDR detection rules for continuous telemetry monitoring.
  • Security Awareness: Alert staff and maintain baseline endpoint hardening across endpoints.
Curated & Verified by CyberNew Threat Intelligence Desk Standard Defense Framework (NIST / MITRE ATT&CK)

Microsoft Teams

Microsoft is working to resolve a known issue that causes delays or blocks some users from opening the Microsoft Teams desktop client on Windows systems.

The company acknowledged this known issue (tracked as TM1466820) at 16:45 EDT on Thursday and advised affected customers to work around it by using the web or mobile platforms.

"Specifically, when first opening Microsoft Teams on Windows devices, some users may be initially unable to load the client or may encounter loading delays of up to two minutes," Microsoft said in an incident report seen by BleepingComputer.

"While we're focused on remediation, affected users may be able to avoid impact by utilizing Microsoft Teams on the web or alternative Teams access methods such as the Teams mobile app."

Microsoft is still analyzing service logs and telemetry data and has also reached out to some affected users to identify the root cause and determine mitigation options.

At the same time, it's investigating an issue preventing Mac users from joining Teams calls and meetings, tracked as TM1466659 and confirmed on Sunday at 08:32 EDT.

While Microsoft initially blamed a code change for causing the Teams call and meeting service infrastructure to fail to process some requests, the company is reassessing the root cause after further review found that this may not be the cause of the impact.

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Source Verification & Original Intelligence

This threat report was reviewed by CyberNew analysts and cross-referenced with primary security disclosures from BleepingComputer.

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