Mika Ayenson
59 lines
2.2 KiB
Python
59 lines
2.2 KiB
Python
# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
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# or more contributor license agreements. Licensed under the Elastic License
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# 2.0; you may not use this file except in compliance with the Elastic License
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# 2.0.
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from . import common
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from . import RtaMetadata
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import time
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metadata = RtaMetadata(
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uuid="d8de8c03-d5d0-4118-8971-32439638d69f",
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platforms=["windows"],
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endpoint=[
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{"rule_name": "Execution from Unusual Directory", "rule_id": "16c84e67-e5e7-44ff-aefa-4d771bcafc0c"},
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{"rule_name": "Binary Masquerading via Untrusted Path", "rule_id": "35dedf0c-8db6-4d70-b2dc-a133b808211f"},
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{"rule_name": "Dynwrapx Image Load via Windows Scripts", "rule_id": "4cd6f758-0057-4e8a-9701-20b6116c2118"},
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{
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"rule_name": "Suspicious Windows Script Interpreter Child Process",
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"rule_id": "83da4fac-563a-4af8-8f32-5a3797a9068e",
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},
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],
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siem=[],
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techniques=["T1055", "T1218", "T1036", "T1059"],
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)
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EXE_FILE = common.get_path("bin", "renamed_posh.exe")
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PS1_FILE = common.get_path("bin", "Invoke-ImageLoad.ps1")
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RENAMER = common.get_path("bin", "rcedit-x64.exe")
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@common.requires_os(metadata.platforms)
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def main():
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cscript = "C:\\Users\\Public\\cscript.exe"
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user32 = "C:\\Windows\\System32\\user32.dll"
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dll = "C:\\Users\\Public\\dynwrapx.dll"
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ps1 = "C:\\Users\\Public\\Invoke-ImageLoad.ps1"
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rcedit = "C:\\Users\\Public\\rcedit.exe"
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common.copy_file(EXE_FILE, cscript)
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common.copy_file(user32, dll)
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common.copy_file(PS1_FILE, ps1)
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common.copy_file(RENAMER, rcedit)
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# Execute command
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common.log("Modifying the OriginalFileName attribute")
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common.execute([rcedit, dll, "--set-version-string", "OriginalFilename", "dynwrapx.dll"])
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common.log("Loading dynwrapx.dll into fake cscript")
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common.execute([cscript, "-c", f"Import-Module {ps1}; Invoke-ImageLoad {dll}"], timeout=10)
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# No idea on why, but after a lot of headaches, I discovered that the dll.pe.original_file_name
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# is only populated if I delay the removal of the dll file
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time.sleep(5)
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common.remove_files(cscript, dll, ps1, rcedit)
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if __name__ == "__main__":
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exit(main())
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