Linux Reverse Shell via Child

[rule]
description = """
Detects the creation of a reverse shell through a shell with suspicious command line arguments. Attackers may spawn
reverse shells to establish persistence onto a target system.
"""
id = "00a97e57-4834-47ec-880d-48ce3783e0b4"
license = "Elastic License v2"
name = "Linux Reverse Shell via Child"
os_list = ["linux"]
reference = ["https://www.elastic.co/security-labs/primer-on-persistence-mechanisms"]
version = "1.0.7"

query = '''
sequence by process.entity_id with maxspan=5s
  [network where event.type == "start" and event.action in ("connection_attempted", "connection_accepted") and 
   process.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish", "socat") and destination.ip != null and 
   not cidrmatch(destination.ip, "127.0.0.0/8", "169.254.0.0/16", "224.0.0.0/4", "::1")]
  [process where event.type == "start" and event.action == "exec" and 
   process.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish") and (
     process.args in ("-i", "-il", "-li") or
     (process.parent.name == "socat" and process.parent.command_line like~ "*exec*")
   )
  ]
'''

min_endpoint_version = "8.5.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 1

[[actions]]
action = "kill_process"
field = "process.parent.entity_id"
state = 0

[[actions]]
action = "kill_process"
field = "process.parent.entity_id"
state = 1

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



[threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1071"
name = "Application Layer Protocol"
reference = "https://attack.mitre.org/techniques/T1071/"


[threat.tactic]
id = "TA0011"
name = "Command and Control"
reference = "https://attack.mitre.org/tactics/TA0011/"

[internal]
min_endpoint_version = "8.5.0"