Managed .NET Code Execution via Windows Script Interpreter

[rule]
description = """
Identifies a suspicious managed code hosting process which could indicate code injection or other form of suspicious
code execution via Windows scripts.
"""
id = "5a898048-d98c-44c6-b7ba-f63a31eb3571"
license = "Elastic License v2"
name = "Managed .NET Code Execution via Windows Script Interpreter"
os_list = ["windows"]
reference = ["https://github.com/med0x2e/GadgetToJScript", "https://github.com/mdsecactivebreach/SharpShooter"]
version = "1.0.29"

query = '''
sequence by process.entity_id with maxspan=2m
 [process where event.type == "start" and
  process.name : ("wscript.exe", "cscript.exe", "mshta.exe", "wmic.exe", "cmstp.exe", "msxsl.exe") and

  /* Only FPs observed so far, similar FPs can be handled via user custom applied exclusions */
  not (process.name : "mshta.exe" and process.parent.name : "Explorer.exe" and
       process.working_directory : "H:\\Code\\SignatureGen\\") and
  not (process.name : "wscript.exe" and process.parent.name : "wscript.exe" and
       process.parent.args : "/ChangedHostBitness" and process.parent.args : "/ALL")]
 [file where event.action == "creation" and
  file.path : "?:\\Users\\*\\Microsoft\\CLR_*\\UsageLogs\\*.exe.log" and
  /*
   CLR Usage Logs are created only for the first time
   the program executes .NET which should reduce noise compared to clr.dll imageload
  */
  file.name : ("wscript.exe.log",
               "cscript.exe.log",
               "mshta.exe.log",
               "wmic.exe.log",
               "cmstp.exe.log",
               "msxsl.exe.log")]
'''

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

[[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 = "T1059.005"
name = "Visual Basic"
reference = "https://attack.mitre.org/techniques/T1059/005/"

[[threat.technique.subtechnique]]
id = "T1059.007"
name = "JavaScript"
reference = "https://attack.mitre.org/techniques/T1059/007/"



[threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1055"
name = "Process Injection"
reference = "https://attack.mitre.org/techniques/T1055/"

[[threat.technique]]
id = "T1220"
name = "XSL Script Processing"
reference = "https://attack.mitre.org/techniques/T1220/"


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

[internal]
min_endpoint_version = "7.15.0"