Hackers Abuse Microsoft Teams External Chats to Access Corporate PCs
Hackers exploit Microsoft Teams external chat settings to gain remote access to corporate PCs.
Cybersecurity researchers have identified a campaign where attackers impersonate IT support in Microsoft Teams external chats to trick employees into granting remote access. This technique leverages the default external chat feature and often follows a 'mail bombing' tactic to create urgency, leading to the installation of malware and implants that exfiltrate corporate network data.
AI summary of the linked source. Not reviewed by an editor. How this works
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The lesson from this incident
Full lessonAttackers exploited Microsoft Teams' default external chat functionality to impersonate IT support staff, using social engineering and mail bombing to create a false sense of urgency. Employees were manipulated into granting remote access, which enabled malware installation and data exfiltration from corporate networks. This attack succeeded not because of a software vulnerability, but because default platform settings were left unrestricted and employees lacked the awareness to verify the legitimacy of unsolicited support requests. The combination of an overlooked configuration and insufficient user training created a highly effective attack pathway that bypassed technical controls entirely.
What helps against this
How we list vendors
- Identity threat detection and response (ITDR)
Attackers who log in with real, stolen credentials get noticed.
- Email security
Phishing, malware and invoice fraud are filtered out before they reach inboxes.
- Security awareness training and phishing simulation
People recognise and report attacks instead of falling for them.
Indicators of Compromise
Extracted by AI from the linked source. Not reviewed by an editor. How this works
- mitre_attack — T1219
- malware — Python-based implant
- mitre_attack — T1059.001
- mitre_attack — T1071.001
- mitre_attack — T1190
- mitre_attack — T1566.002
- mitre_attack — T1566.001
- mitre_attack — T1003
- mitre_attack — T1087.002
- mitre_attack — T1087.001