Powershell Execution via Named Pipe

[rule]
description = "Identifies the execution of a PowerShell script that allow remote command execution via named pipe."
id = "c286b078-793f-4c51-a49a-27948e0ed741"
license = "Elastic License v2"
name = "Powershell Execution via Named Pipe"
os_list = ["windows"]
reference = ["https://github.com/threatexpress/invoke-pipeshell/tree/master"]
version = "1.0.3"

query = '''
api where process.Ext.api.name == "AmsiScanBuffer" and
 (process.name in~ ("powershell.exe") or process.Ext.api.parameters.app_name == "PowerShell") and
  process.Ext.api.parameters.buffer : ("*Pipes.NamedPipeClientStream*.Connect(*", "*Pipes.NamedPipeServerStream*WaitForConnection*") and
  process.Ext.api.parameters.buffer : "*.StreamReader*" and process.Ext.api.parameters.buffer : "*.StreamWriter*" and
  process.Ext.api.parameters.buffer : "*.ReadLine*" and process.Ext.api.parameters.buffer : "*.WriteLine*" and
  process.Ext.api.parameters.buffer : ("*while(*", "*while (*") and
  not (process.command_line : "*AZQBjAHQAIABTAHkAcwB0AGUAbQAuAEkATwAuAFAAaQBwAGUAcwAuAE4AYQBtAGUAZABQAGkAcABlAFMAZQByAHYAZQByAFMAdAByAGUAYQBtACgAJwBpAG4AcwBwA*" and
       process.Ext.api.parameters.size == 3354) and
  not (process.parent.executable : ("?:\\Windows\\System32\\msiexec.exe", "?:\\Windows\\SysWOW64\\msiexec.exe") and
       process.Ext.api.parameters.content_name : "?:\\WINDOWS\\SystemTemp\\ps*.ps1" and user.id == "S-1-5-18")
'''

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

[[optional_actions]]
action = "rollback"
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 = "T1059.001"
name = "PowerShell"
reference = "https://attack.mitre.org/techniques/T1059/001/"



[threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1021"
name = "Remote Services"
reference = "https://attack.mitre.org/techniques/T1021/"
[[threat.technique.subtechnique]]
id = "T1021.002"
name = "SMB/Windows Admin Shares"
reference = "https://attack.mitre.org/techniques/T1021/002/"



[threat.tactic]
id = "TA0008"
name = "Lateral Movement"
reference = "https://attack.mitre.org/tactics/TA0008/"

[internal]
min_endpoint_version = "8.16.0"