> 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/potential-ntlm-relay-attack.md).
# Potential NTLM Relay Attack
### Synopsis
| Field | Value |
| -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | 10 Minutes |
| Deduplication Period | 1 Day |
| Required Data | XDR Agent |
| Detection Modules | Identity Analytics |
| 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 | Informational |
### Description
Multiple NTLM authentications were made to the same workstation and user from different IPs. This might indicate a potential NTLM Relay attack.
### 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
* Ensure that the alerted host is not a NAT device or proxy that replicates or forwards network traffic as part of its expected operational behavior.
* Check if the workstation supports weak, outdated versions of NTLM.
* Check for network activity to and from the suspicious IP address and workstation, to verify if they were compromised.
* Check for process activity to and from the suspicious IP address to verify if it was compromised.
* Check for changes in the network configurations, including indicators of poisoning attacks.
* Monitor closely the actions of the potentially compromised user account for any anomalous behavior.
### Variations
NTLM Relay Attack using a sensitive user and a vulnerable package
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| 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 | Medium |
**Description**
Multiple NTLM authentications were made to the same workstation and sensitive user from different IPs using a vulnerable NTLM package. This might indicate a potential NTLM Relay attack.
**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**
* Ensure that the alerted host is not a NAT device or proxy that replicates or forwards network traffic as part of its expected operational behavior.
* Check if the workstation supports weak, outdated versions of NTLM.
* Check for network activity to and from the suspicious IP address and workstation, to verify if they were compromised.
* Check for process activity to and from the suspicious IP address to verify if it was compromised.
* Check for changes in the network configurations, including indicators of poisoning attacks.
* Monitor closely the actions of the potentially compromised user account for any anomalous behavior.
Potential NTLM Relay Attack using a vulnerable package
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| 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**
Multiple NTLM authentications were made to the same workstation and user from different IPs using a vulnerable NTLM package. This might indicate a potential NTLM Relay attack.
**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**
* Ensure that the alerted host is not a NAT device or proxy that replicates or forwards network traffic as part of its expected operational behavior.
* Check if the workstation supports weak, outdated versions of NTLM.
* Check for network activity to and from the suspicious IP address and workstation, to verify if they were compromised.
* Check for process activity to and from the suspicious IP address to verify if it was compromised.
* Check for changes in the network configurations, including indicators of poisoning attacks.
* Monitor closely the actions of the potentially compromised user account for any anomalous behavior.
Potential NTLM Relay Attack using a sensitive user
**Synopsis**
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| 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**
Multiple NTLM authentications were made to the same workstation and sensitive user from different IPs. This might indicate a potential NTLM Relay attack.
**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**
* Ensure that the alerted host is not a NAT device or proxy that replicates or forwards network traffic as part of its expected operational behavior.
* Check if the workstation supports weak, outdated versions of NTLM.
* Check for network activity to and from the suspicious IP address and workstation, to verify if they were compromised.
* Check for process activity to and from the suspicious IP address to verify if it was compromised.
* Check for changes in the network configurations, including indicators of poisoning attacks.
* Monitor closely the actions of the potentially compromised user account for any anomalous behavior.
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