Microsoft Details the Cause of This Week’s Microsoft 365 Outage

A major outage that took place earlier this week made it impossible for users to access their Microsoft 365 services, and now Microsoft has published the results of its investigation to reveal what exactly went wrong.

The outage impacted the majority of Microsoft 365 services, including Microsoft Teams, Exchange Online, SharePoint Online, Microsoft Graph API, and OneDrive for Business.

Microsoft says users encountered delays and failures when trying to log in, as well as errors when performing searches or accessing the calendar features.

The software giant explains that users in Western Europe were mostly affected by the outage, however, subscribers in other parts of the world also experienced similar issues when trying to access their Microsoft 365 accounts.

“We've confirmed from our updated service monitoring that all services remain healthy following the targeted restarts. Additionally, we completed our investigation into the potential remaining impact to Outl...

nmap -sV --script vuln -p- <target-network>

tail -f /var/log/suricata/fast.log | grep <cve>

Check Vendor Security Advisory Bulletin

title: Detect Exploitation - Microsoft Details the Cause of This Week’s Microsoft 365 Outage
id: 5f73d964-ef03-46fc-9c91-1ab2c7592359
status: experimental
description: Automatisch generierte SIEM-Erkennungsregel basierend auf CTI Intelligence
references:
  - https://tsecurity.de/
author: iShareStuff CTI Automated Detection Engine
date: 2026-09-24
logsource:
  category: network_connection
  product: any
detection:
  selection:
      CommandLine|contains:
        - 'exploit'
  condition: selection
falsepositives:
  - Legitime administrative Zugriffe oder Penetrationstests
level: high
tags:
  - attack.initial_access

rule CTI_Threat_Indicator {
    meta:
        author = "iShareStuff CTI Automated Detection Engine"
        date = "2026-09-24"
        description = "YARA Signature for "
    strings:
        $str = "Microsoft Details the Cause of" ascii wide
    condition:
        any of them
}