> 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-email-display-name-impersonation-of-internal-personnel.md).

# External email display name impersonation of internal personnel

### Synopsis

| Field                | Value                                  |
| -------------------- | -------------------------------------- |
| Activation Period    | 14 Days                                |
| Training Period      | 30 Days                                |
| Test Period          | N/A (single event)                     |
| Deduplication Period | 1 Hour 30 Minutes                      |
| Required Data        | Microsoft 365 Emails                   |
| Detection Modules    | Email                                  |
| Detector Tags        | Employee Impersonation, Spear Phishing |
| ATT\&CK Tactic       | Defense Evasion (TA0005)               |
| ATT\&CK Technique    | Impersonation (T1656)                  |
| Severity             | Informational                          |

### Description

Potential email attempting to impersonate an internal user has been detected.

* The sender's email address appears unusual in relation to the provided display name, suggesting a possible impersonation attempt targeting an internal user.

### Attacker's Goals

Impersonate internal users or familiar individuals and trick them into clicking on malicious links or attachments.

### Investigative actions

* Check the email address for any unusual spellings, missing letters, or unknown domains.
* Examine the sender's IP address and reputation.
* Verify whether the sender's IP address has appeared in different log sources before, and if it is recognizable.
* If the message contains attachments or links, scrutinize them for any suspicious indications.
* Monitor further actions taken, such as file downloads or access to potentially malicious links.

### Variations

<details>

<summary>External email display name impersonation of internal personnel, using a public provider</summary>

**Synopsis**

| Field             | Value                    |
| ----------------- | ------------------------ |
| ATT\&CK Tactic    | Defense Evasion (TA0005) |
| ATT\&CK Technique | Impersonation (T1656)    |
| Severity          | Informational            |

**Description**

Potential email attempting to impersonate an internal user has been detected.

* The sender's email address appears unusual in relation to the provided display name, suggesting a possible impersonation attempt targeting an internal user.

**Attacker's Goals**

Impersonate internal users or familiar individuals and trick them into clicking on malicious links or attachments.

**Investigative actions**

* Check the email address for any unusual spellings, missing letters, or unknown domains.
* Examine the sender's IP address and reputation.
* Verify whether the sender's IP address has appeared in different log sources before, and if it is recognizable.
* If the message contains attachments or links, scrutinize them for any suspicious indications.
* Monitor further actions taken, such as file downloads or access to potentially malicious links.

</details>


---

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