> 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-ssh-downgrade.md).
# Suspicious SSH Downgrade
### Synopsis
| Field | Value |
| -------------------- | ---------------------------------------------------------------------- |
| Activation Period | 14 Days |
| Training Period | 30 Days |
| Test Period | N/A (single event) |
| Deduplication Period | 1 Day |
| Required Data | Palo Alto Networks Firewall EAL Logs |
| Detector Tags | NDR Lateral Movement Analytics |
| ATT\&CK Tactic | Lateral Movement (TA0008), Defense Evasion (TA0005) |
| ATT\&CK Technique | Remote Services (T1021), Impair Defenses: Downgrade Attack (T1562.010) |
| Severity | Low |
### Description
The endpoint asked for an ssh downgrade, ssh downgrade may enable attackers to perform attacks such as data decryption, man in the middle, session hijack, replay attack and more.
### Attacker's Goals
* Attackers may attempt to move laterally over the network by exploiting problems in a lower version of SSH.
### Investigative actions
Audit the authentication attempts in the SSH server from the alerted host. If the source host authenticated to the SSH server, it may indicate that the attacker managed to connect to the remote host maliciously.
### Variations
A Host Performed an SSH Downgrade For The First Time In The Last 30 Days
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008), Defense Evasion (TA0005) |
| ATT\&CK Technique | Remote Services (T1021), Impair Defenses: Downgrade Attack (T1562.010) |
| Severity | Low |
**Description**
The endpoint asked for an ssh downgrade, ssh downgrade may enable attackers to perform attacks such as data decryption, man in the middle, session hijack, replay attack and more. With a lower version than the source host used in the past.
**Attacker's Goals**
* Attackers may attempt to move laterally over the network by exploiting problems in a lower version of SSH.
**Investigative actions**
Audit the authentication attempts in the SSH server from the alerted host. If the source host authenticated to the SSH server, it may indicate that the attacker managed to connect to the remote host maliciously.
A Target Server Performed an SSH Downgrade For The First Time In The Last 30 Days
**Synopsis**
| Field | Value |
| ----------------- | ---------------------------------------------------------------------- |
| ATT\&CK Tactic | Lateral Movement (TA0008), Defense Evasion (TA0005) |
| ATT\&CK Technique | Remote Services (T1021), Impair Defenses: Downgrade Attack (T1562.010) |
| Severity | Low |
**Description**
The endpoint asked for an ssh downgrade, ssh downgrade may enable attackers to perform attacks such as data decryption, man in the middle, session hijack, replay attack and more. With a lower version than the remote host used in the past.
**Attacker's Goals**
* Attackers may attempt to move laterally over the network by exploiting problems in a lower version of SSH.
**Investigative actions**
Audit the authentication attempts in the SSH server from the alerted host. If the source host authenticated to the SSH server, it may indicate that the attacker managed to connect to the remote host maliciously.
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