Potential SSH Brute Force Detected on Privileged Accountedit

Identifies multiple consecutive login failures targeting a root user account from the same source address and within a short time interval. Adversaries will often brute force login attempts on privileged accounts with a common or known password, in an attempt to gain privileged access to systems.

Rule type: eql

Rule indices:

  • auditbeat-*
  • logs-system.auth-*

Severity: high

Risk score: 73

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100


  • Elastic
  • Host
  • Linux
  • Threat Detection
  • Credential Access

Version: 1

Added (Elastic Stack release): 8.5.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guideedit

## Triage and analysis

### Investigating Potential SSH Brute Force Attack on Privileged Account

The rule identifies consecutive SSH login failures targeting a privileged (root) account from the same source IP
address to the same target host indicating brute force login attempts.

#### Possible investigation steps

- Investigate the login failure on privileged account(s).
- Investigate the source IP address of the failed ssh login attempt(s).
- Investigate other alerts associated with the user/host during the past 48 hours.
- Identify the source and the target computer and their roles in the IT environment.

### False positive analysis
- Authentication misconfiguration or obsolete credentials.
- Service account password expired.
- Infrastructure or availability issue.

### Response and remediation
- Initiate the incident response process based on the outcome of the triage.
- Isolate the involved hosts to prevent further post-compromise behavior.
- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are
- Reset passwords for these accounts and other potentially compromised credentials.
- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and
malware components.
- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the
mean time to respond (MTTR).

Rule queryedit

sequence by host.id, source.ip with maxspan=10s [authentication
where event.action in ("ssh_login", "user_login") and
event.outcome == "failure" and source.ip != null and source.ip !=
"" and source.ip != "::" and user.name in ("*root*" ,
"*admin*")] with runs=3

Threat mappingedit