SigmaHQ/rules-unsupported/sysmon_process_reimaging.yml

action: global
title: Defense evasion via process reimaging
id: 7fa4f550-850e-4117-b543-428c86ebb849
description: Detects process reimaging defense evasion technique
# where
#             selection1: ImageFileName != selection1: OriginalFileName
#             selection1: ParentProcessGuid = selection2: ProcessGuid
#             selection1: Image = selection2: TargetFilename
# and new field ImageFileName is coming from enrichment
#             selection1: Image = ^.+\\<ImageFileName>$
# Rule must trigger if selection1 and selection2 both occurs in timeframe of 120 sec.
# Rule logic is currently not supported by SIGMA.
# Sysmon v.10.0 or newer is required for proper detection.
status: experimental
author: Alexey Balandin, oscd.community
references:
    - https://securingtomorrow.mcafee.com/other-blogs/mcafee-labs/in-ntdll-i-trust-process-reimaging-and-endpoint-security-solution-bypass/
tags:
    - attack.defense_evasion
date: 2019/10/25
detection:
    condition: all of them
falsepositives:
    - unknown
level: high
---
logsource:
    product: windows
    service: sysmon
detection:
    selection1:
        category: process_creation
fields:
    - Image
    - OriginalFileName
    - ParentProcessGuid
new_fields:
    - ImageFileName
---
logsource:
    product: windows
    service: sysmon
detection:
    selection2:
        EventID: 11
fields:
    - ProcessGuid
    - TargetFilename