Suspicious Binary Execution via SSH

[rule]
description = """
Detects SSH sessions executing suspicious binaries followed by outbound network connections. This pattern indicates
potential post-exploitation activity via compromised SSH access.
"""
id = "050a7053-a119-43fc-ad14-9a0c4944a9b8"
license = "Elastic License v2"
name = "Suspicious Binary Execution via SSH"
os_list = ["macos"]
version = "1.0.8"

query = '''
sequence by process.entity_id with maxspan=15s
[process where event.type == "start" and event.action == "exec" and process.parent.name in ("ssh", "sshd", "sshd-session") and
 (process.name like~ ("osascript", "curl", "nscurl", "wget", "perl", "node") or (process.code_signature.exists == false or
  process.code_signature.trusted == false)) and
 not process.executable like~ ("/opt/homebrew/Cellar/*", "/usr/local/Cellar/*", "/Users/*/homebrew/Cellar/*", "/usr/local/libexec/ssh-sk-helper") and 
 not process.Ext.effective_parent.executable in ("/Applications/Codex.app/Contents/MacOS/Codex", "/Applications/Cursor.app/Contents/MacOS/Cursor") and 
 process.hash.sha256 != "cc2b7231c9f1696e24c0c05cbc93ec88172ba6fa102b0fbbdc8ed95ee564b4d6"
 ]
 [network where event.type == "start" and
   not cidrmatch(destination.ip, 
       "240.0.0.0/4", "233.252.0.0/24", "224.0.0.0/4", "198.19.0.0/16", "192.18.0.0/15", 
       "192.0.0.0/24", "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", 
       "192.0.2.0/24", "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", 
       "100.64.0.0/10", "192.175.48.0/24", "198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24",
       "::1", "FE80::/10", "FF00::/8")]
'''

min_endpoint_version = "8.16.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[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/"

[internal]
min_endpoint_version = "8.16.0"