Linux Restricted Shell Breakout via busybox Shell Evasion
editLinux Restricted Shell Breakout via busybox Shell Evasion
editIdentifies Linux binary busybox abuse to break out from restricted environments by spawning an interactive system shell.The busybox is software utility suite that provides several Unix utilities in a single executable file and the activity of spawing a shell is not a standard use of this binary by a user or system administrator. It indicates a potentially malicious actor attempting to improve the capabilities or stability of their access.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Linux
- Threat Detection
- Execution
- GTFOBins
Version: 1
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editprocess where event.type == "start" and process.name == "busybox" and process.args_count == 2 and process.args in ("/bin/sh", "/bin/ash", "sh", "ash")
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/
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Sub-technique:
- Name: Unix Shell
- ID: T1059.004
- Reference URL: https://attack.mitre.org/techniques/T1059/004/