rules/_deprecated/execution_c89_c99_binary.toml

[metadata]
creation_date = "2022/03/15"
deprecation_date = "2022/05/09"
maturity = "deprecated"
updated_date = "2022/05/09"

[rule]
author = ["Elastic"]
description = """
Identifies Linux binary c89/c99 abuse to break out from restricted environments by spawning an interactive system
shell.The c89/c99 utility is an interface to the standard C compilation system 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.
"""
from = "now-9m"
index = ["logs-endpoint.events.*"]
language = "eql"
license = "Elastic License v2"
name = "Linux Restricted Shell Breakout via c89/c99 Shell evasion"
references = ["https://gtfobins.github.io/gtfobins/c89/", "https://gtfobins.github.io/gtfobins/c99/"]
risk_score = 47
rule_id = "1859ce38-6a50-422b-a5e8-636e231ea0cd"
severity = "medium"
tags = ["Elastic", "Host", "Linux", "Threat Detection", "Execution", "GTFOBins"]
timestamp_override = "event.ingested"
type = "eql"

query = '''
process where event.type == "start" and process.name in ("sh", "dash", "bash") and
  process.parent.name in ("c89","c99") and process.parent.args == "-wrapper" and
  process.parent.args in ("sh,-s", "bash,-s", "dash,-s", "/bin/sh,-s", "/bin/bash,-s", "/bin/dash,-s")
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"
[[rule.threat.technique.subtechnique]]
id = "T1059.004"
name = "Unix Shell"
reference = "https://attack.mitre.org/techniques/T1059/004/"



[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"