> 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/machine-account-ntlm-relay.md).

# Machine Account NTLM Relay

### Synopsis

| Field                | Value                                                                                                                                       |
| -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| Activation Period    | 14 Days                                                                                                                                     |
| Training Period      | 30 Days                                                                                                                                     |
| Test Period          | 10 Minutes                                                                                                                                  |
| Deduplication Period | 1 Day                                                                                                                                       |
| Required Data        | <p>Requires one of the following data sources:<br>Palo Alto Networks Firewall traffic Logs OR XDR Agent</p>                                 |
| ATT\&CK Tactic       | Credential Access (TA0006), Lateral Movement (TA0008)                                                                                       |
| ATT\&CK Technique    | Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay (T1557.001), Use Alternate Authentication Material: Pass the Hash (T1550.002) |
| Severity             | Low                                                                                                                                         |

### Description

An NTLM NTProofStr was seen from more than one source. This indicates that machine account NTLM authentication data has been relayed.

### Attacker's Goals

The attacker is attempting a man-in-the-middle NTLM relay attack to intercept authentication attempts and move laterally within an environment.

### Investigative actions

* Check that the alerted host is not a NAT or a proxy that duplicates traffic as part of its normal behavior.
* Check if the protocols used are vulnerable to an NTLM relay attack (e.g. LDAP, SMB).
* Ensure that SMB signing is enabled in the case of a possible SMB relay attack.


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