> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/analytics-alerts/alerts-by-name/possible-multistage-attack-in-microsoft-teams.md).

# Possible multistage attack in Microsoft Teams

### Synopsis

| Field                | Value                   |
| -------------------- | ----------------------- |
| Activation Period    | 14 Days                 |
| Training Period      | 30 Days                 |
| Test Period          | 12 Hours                |
| Deduplication Period | 1 Day                   |
| Required Data        | Office 365 Audit        |
| Detection Modules    | Identity Threat Module  |
| Detector Tags        | Microsoft Teams         |
| ATT\&CK Tactic       | Initial Access (TA0001) |
| ATT\&CK Technique    | Phishing (T1566)        |
| Severity             | Low                     |

### Description

Possible multistage attack in Microsoft Teams.

### Attacker's Goals

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

### Investigative actions

* 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.

### Variations

<details>

<summary>Malicious activity had been detected with strong indicators</summary>

**Synopsis**

| Field             | Value                   |
| ----------------- | ----------------------- |
| ATT\&CK Tactic    | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566)        |
| Severity          | Medium                  |

**Description**

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

**Attacker's Goals**

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

**Investigative actions**

* 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.

</details>


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