50 lines
1.7 KiB
TOML
50 lines
1.7 KiB
TOML
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[metadata]
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creation_date = "2022/03/22"
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maturity = "production"
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updated_date = "2022/03/22"
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[rule]
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author = ["Elastic"]
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description = """
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Identifies Linux binary flock abuse to break out from restricted environments by spawning an interactive system
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shell.The flock utility allows us to manage advisory file locks in shell scripts or on the command line and the activity
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of spawing a shell is not a standard use of this binary by a user or system administrator. It indicates a potentially
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malicious actor attempting to improve the capabilities or stability of their access.
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"""
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from = "now-9m"
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index = ["logs-endpoint.events.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "Linux Restricted Shell Breakout via flock Shell evasion"
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references = ["https://gtfobins.github.io/gtfobins/flock/"]
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risk_score = 47
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rule_id = "f52362cd-baf1-4b6d-84be-064efc826461"
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severity = "medium"
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tags = ["Elastic", "Host", "Linux", "Threat Detection", "Execution", "GTFOBins"]
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timestamp_override = "event.ingested"
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type = "eql"
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query = '''
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process where event.type == "start" and process.parent.name == "flock" and process.parent.args == "-u" and process.parent.args == "/" and process.parent.args in ("/bin/sh", "/bin/bash", "/bin/dash", "sh", "bash", "dash") and process.name in ("bash", "dash", "sh")
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'''
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[[rule.threat.technique]]
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id = "T1059"
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name = "Command and Scripting Interpreter"
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reference = "https://attack.mitre.org/techniques/T1059/"
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[[rule.threat.technique.subtechnique]]
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id = "T1059.004"
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name = "Unix Shell"
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reference = "https://attack.mitre.org/techniques/T1059/004/"
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[rule.threat.tactic]
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id = "TA0002"
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name = "Execution"
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reference = "https://attack.mitre.org/tactics/TA0002/"
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