IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Suspicious which Enumerationedit
This rule monitors for the usage of the which command with an unusual amount of process arguments. Attackers may leverage the which command to enumerate the system for useful installed utilities that may be used after compromising a system to escalate privileges or move latteraly across the network.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: low
Risk score: 21
Runs every: 60m
Searches indices from: now-119m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References: None
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Discovery
- Data Source: Elastic Defend
- Rule Type: BBR
Version: 2
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule queryedit
process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and
process.name == "which" and process.args_count >= 10
/* potential tuning if rule would turn out to be noisy
and process.args in ("nmap", "nc", "ncat", "netcat", nc.traditional", "gcc", "g++", "socat") and
process.parent.name in ("bash", "dash", "ash", "sh", "tcsh", "csh", "zsh", "ksh", "fish")
*/
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Discovery
- ID: TA0007
- Reference URL: https://attack.mitre.org/tactics/TA0007/
-
Technique:
- Name: System Information Discovery
- ID: T1082
- Reference URL: https://attack.mitre.org/techniques/T1082/