Binary Proxy Execution via Pester

[rule]
description = """
Identifies the execution of a binary via the Pester PowerShell module. Adversaries may bypass process and
signature-based defenses by proxying execution of malicious content with signed, or otherwise trusted, binaries.
"""
id = "bbc7e649-dc8e-401f-a6e4-d2d668aef4ac"
license = "Elastic License v2"
name = "Binary Proxy Execution via Pester"
os_list = ["windows"]
reference = ["https://lolbas-project.github.io/lolbas/Scripts/pester/"]
version = "1.0.5"

query = '''
process where event.action == "start" and
(
 (process.parent.name : "powershell.exe" and
  process.parent.command_line : "powershell*WindowsPowerShell\\Modules*\\Pester.psm1*;*" and
 not process.executable : ("?:\\Windows\\Microsoft.NET\\Framework*\\csc.exe", "?:\\Windows\\Sys*\\conhost.exe")) or

 (process.name : "powershell.exe" and process.command_line : "*\\Pester.psm1*;*http*")
)
'''

min_endpoint_version = "7.15.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1218"
name = "System Binary Proxy Execution"
reference = "https://attack.mitre.org/techniques/T1218/"


[threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"

[internal]
min_endpoint_version = "7.15.0"