Possible multistage attack in Microsoft Teams

Cortex XDR Analytics Alert Reference by Alert name

Product

Cortex XDR

Last date published

2026-02-02

Possible multistage attack in Microsoft Teams.

Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.

Verify the suspicious activity to validate the legitimacy of the user's actions.
Review Teams chat logs and meeting invites for interactions with external tenants, focusing on unusual file sharing or unsolicited links.
Hunt for known phishing indicators (suspicious domains, URL patterns, or IPs) in the Teams messages and linked content.
Evaluate the external tenant reputation.
Check for anomalous MS Teams actions like suspicious application installation, message extraction, policy changes or internal spear phishing attempts linked to the user post-login.
Follow further actions done by the account.

Malicious Microsoft Teams activity detected across multiple indicators, the activities have strong indications of a malicious action.

Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.

Verify the suspicious activity to validate the legitimacy of the user's actions.
Review Teams chat logs and meeting invites for interactions with external tenants, focusing on unusual file sharing or unsolicited links.
Hunt for known phishing indicators (suspicious domains, URL patterns, or IPs) in the Teams messages and linked content.
Evaluate the external tenant reputation.
Check for anomalous MS Teams actions like suspicious application installation, message extraction, policy changes or internal spear phishing attempts linked to the user post-login.
Follow further actions done by the account.