sigmamediumHunting

File or Folder Permissions Modifications

Detects a file or folder's permissions being modified or tampered with.

MITRE ATT&CK

defense-evasion

Detection Query

selection_1:
  Image|endswith:
    - \cacls.exe
    - \icacls.exe
    - \net.exe
    - \net1.exe
  CommandLine|contains:
    - /grant
    - /setowner
    - /inheritance:r
selection_2:
  Image|endswith: \attrib.exe
  CommandLine|contains: -r
selection_3:
  Image|endswith: \takeown.exe
filter_optional_dynatrace_1:
  CommandLine|endswith: ICACLS C:\ProgramData\dynatrace\gateway\config\connectivity.history /reset
filter_optional_dynatrace_2:
  CommandLine|contains|all:
    - "ICACLS C:\\ProgramData\\dynatrace\\gateway\\config\\config.properties
      /grant :r "
    - S-1-5-19:F
filter_optional_vscode:
  CommandLine|contains:
    - \AppData\Local\Programs\Microsoft VS Code
    - :\Program Files\Microsoft VS Code
filter_optional_avira:
  CommandLine|contains:
    - :\Program Files (x86)\Avira
    - :\Program Files\Avira
condition: 1 of selection_* and not 1 of filter_optional_*

Author

Jakob Weinzettl, oscd.community, Nasreddine Bencherchali (Nextron Systems)

Created

2019-10-23

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.defense-evasionattack.t1222.001detection.threat-hunting

Raw Content

title: File or Folder Permissions Modifications
id: 37ae075c-271b-459b-8d7b-55ad5f993dd8
status: test
description: Detects a file or folder's permissions being modified or tampered with.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.001/T1222.001.md
    - https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/hh750728(v=ws.11)
    - https://github.com/swagkarna/Defeat-Defender-V1.2.0/tree/ae4059c4276da6f6303b8f53cdff085ecae88a91
author: Jakob Weinzettl, oscd.community, Nasreddine Bencherchali (Nextron Systems)
date: 2019-10-23
modified: 2023-11-21
tags:
    - attack.defense-evasion
    - attack.t1222.001
    - detection.threat-hunting
logsource:
    category: process_creation
    product: windows
detection:
    selection_1:
        Image|endswith:
            - '\cacls.exe'
            - '\icacls.exe'
            - '\net.exe' # "grant" Option available when used with "net share"
            - '\net1.exe' # "grant" Option available when used with "net share"
        CommandLine|contains:
            - '/grant'
            - '/setowner'
            - '/inheritance:r' # Remove all inherited ACEs
    selection_2:
        Image|endswith: '\attrib.exe'
        CommandLine|contains: '-r'
    selection_3:
        Image|endswith: '\takeown.exe' # If this generates FP in your environment. Comment it out or add more suspicious flags and locations
    filter_optional_dynatrace_1:
        CommandLine|endswith: 'ICACLS C:\ProgramData\dynatrace\gateway\config\connectivity.history /reset'
    filter_optional_dynatrace_2:
        CommandLine|contains|all:
            - 'ICACLS C:\ProgramData\dynatrace\gateway\config\config.properties /grant :r '
            - 'S-1-5-19:F'
    filter_optional_vscode:
        CommandLine|contains:
            - '\AppData\Local\Programs\Microsoft VS Code'
            - ':\Program Files\Microsoft VS Code'
    filter_optional_avira:
        CommandLine|contains:
            - ':\Program Files (x86)\Avira'
            - ':\Program Files\Avira'
    condition: 1 of selection_* and not 1 of filter_optional_*
falsepositives:
    - Users interacting with the files on their own (unlikely unless privileged users).
    - Dynatrace app
level: medium