> 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/suspicious-ntlm-authentication-with-machine-account.md).

# Suspicious NTLM authentication with machine account

### Synopsis

| Field                | Value                                                                                                   |
| -------------------- | ------------------------------------------------------------------------------------------------------- |
| Activation Period    | 14 Days                                                                                                 |
| Training Period      | 30 Days                                                                                                 |
| Test Period          | N/A (single event)                                                                                      |
| Deduplication Period | 1 Day                                                                                                   |
| Required Data        | <p>Requires one of the following data sources:<br>Palo Alto Networks Firewall EAL Logs OR XDR Agent</p> |
| Detection Modules    | Identity Analytics                                                                                      |
| ATT\&CK Tactic       | Credential Access (TA0006)                                                                              |
| ATT\&CK Technique    | Forced Authentication (T1187)                                                                           |
| Severity             | Informational                                                                                           |

### Description

A suspicious NTLM authentication attempt was made by a machine account.

### Attacker's Goals

An attacker aims to exploit authentication protocols to steal credentials and enable lateral movement within the network.

### Investigative actions

* Identify the source and target users and hosts involved in the NTLM authentication attempt.
* Monitor the users associated with the authentication for any further suspicious activities or unauthorized actions.
* Look for earlier connections to the source which may cause it to initiate the session.
* Investigate the root cause of the behavior and determine if it can be mitigated or blocked in the future.

### Variations

<details>

<summary>Rare and sensitive NTLM authentication with machine account</summary>

**Synopsis**

| Field             | Value                         |
| ----------------- | ----------------------------- |
| ATT\&CK Tactic    | Credential Access (TA0006)    |
| ATT\&CK Technique | Forced Authentication (T1187) |
| Severity          | Low                           |

**Description**

A rare and sensitive NTLM authentication attempt was made by a machine account.

**Attacker's Goals**

An attacker aims to exploit authentication protocols to steal credentials and enable lateral movement within the network.

**Investigative actions**

* Check for signs of data exfiltration from any internet-facing destination server.
* Identify the source and target users and hosts involved in the NTLM authentication attempt.
* Monitor the users associated with the authentication for any further suspicious activities or unauthorized actions.
* Look for earlier connections to the source which may cause it to initiate the session.
* Investigate the root cause of the behavior and determine if it can be mitigated or blocked in the future.

</details>


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