> 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/external-user-created-a-microsoft-teams-conversation-with-suspicious-operations.md).
# External user created a Microsoft Teams conversation with suspicious operations
### Synopsis
| Field | Value |
| -------------------- | ----------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | 3 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 | Informational |
### Description
An external user created a Microsoft Teams conversation with users in the organization with additional suspicious operations.
### Attacker's Goals
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
### Investigative actions
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
### Variations
An external user initiated a Microsoft Teams chat in which a suspicious link was shared and a member was removed
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Low |
**Description**
An external user initiated a Microsoft Teams chat in which a link, with a domain that hasn't been seen the last 30 days, was shared, and a member was removed.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
An external user created a chat and shortly after sent a link with a newly seen domain name
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Low |
**Description**
An external user created a chat and shortly after sent a link to a conversation via Microsoft Teams that refers to a domain that was seen for the first time in the past 30 days.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
An external user initiated a Microsoft Teams chat in which a link was shared and a member was removed
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Low |
**Description**
An external user initiated a Microsoft Teams chat in which a link with a rarely seen domain was shared, and a member was removed.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
An external user created a chat then sent a link with a file for the first time via Microsoft Teams
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Low |
**Description**
An external user sent a link for the first time during the past 30 days in a Microsoft Teams conversation, and the link points to a file.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
An external user created a chat with a suspicious user or chat name and then sent a link via Microsoft Teams
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Low |
**Description**
An external user created a chat with a suspicious user or chat name and sent a link in Microsoft Teams, which can be a phishing attempt.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
External user created a Microsoft Teams conversation with a suspicious user or chat name and shortly after removed a user from it
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Low |
**Description**
An external user created a conversation with a suspicious user or chat name, and then removed a member, which could indicate potential suspicious activity.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
An external user created a chat then sent a link via Microsoft Teams
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Informational |
**Description**
An external user created a chat and sent a link in Microsoft Teams, which can be a phishing attempt.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
An external user created a chat and then sent a link via Microsoft Teams
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Informational |
**Description**
An external user created a chat and sent a link in Microsoft Teams, which can be a phishing attempt.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
External user created a Microsoft Teams conversation and shortly after removed a user from it
**Synopsis**
| Field | Value |
| ----------------- | ----------------------- |
| ATT\&CK Tactic | Initial Access (TA0001) |
| ATT\&CK Technique | Phishing (T1566) |
| Severity | Informational |
**Description**
An external user created a conversation and then removed a member, which could indicate potential suspicious activity.
**Attacker's Goals**
Attackers may leverage Microsoft Teams to conduct phishing attacks by exploiting trusted communication channels with users inside the organization.
**Investigative actions**
* Confirm that the tenant and user are authorized to start a conversation with users in the organization.
* Verify whether any user was removed from the conversation, and determine the reason for their removal.
* Verify the content of the conversation and validate that there is no phishing attempt being made.
* Inspect links and URLs that might have been sent in the conversation.
* Check external domain reputation.
* Review past communication from the external user.
* Follow further actions done by the account.
---
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