Detection rules › Sigma

Copying Sensitive Files with Credential Data

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Teymur Kheirkhabarov, Daniil Yugoslavskiy, oscd.community
Source
github.com/SigmaHQ/sigma

Files with well-known filenames (sensitive files with credential data) copying

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Copying Sensitive Files with Credential Data
id: e7be6119-fc37-43f0-ad4f-1f3f99be2f9f
status: test
description: Files with well-known filenames (sensitive files with credential data) copying
references:
    - https://room362.com/post/2013/2013-06-10-volume-shadow-copy-ntdsdit-domain-hashes-remotely-part-1/
    - https://www.slideshare.net/heirhabarov/hunting-for-credentials-dumping-in-windows-environment
    - https://dfironthemountain.wordpress.com/2018/12/06/locked-file-access-using-esentutl-exe/
    - https://github.com/LOLBAS-Project/LOLBAS/blob/2cc01b01132b5c304027a658c698ae09dd6a92bf/yml/OSBinaries/Esentutl.yml
author: Teymur Kheirkhabarov, Daniil Yugoslavskiy, oscd.community
date: 2019-10-22
modified: 2024-06-04
tags:
    - attack.credential-access
    - attack.t1003.002
    - attack.t1003.003
    - car.2013-07-001
    - attack.s0404
logsource:
    category: process_creation
    product: windows
detection:
    selection_esent_img:
        - Image|endswith: '\esentutl.exe'
        - OriginalFileName: '\esentutl.exe'
    selection_esent_cli:
        CommandLine|contains|windash:
            - 'vss'
            - ' /m '
            - ' /y '
    selection_susp_paths:
        CommandLine|contains:
            - '\config\RegBack\sam'
            - '\config\RegBack\security'
            - '\config\RegBack\system'
            - '\config\sam'
            - '\config\security'
            - '\config\system '        # space needed to avoid false positives with \config\systemprofile\
            - '\repair\sam'
            - '\repair\security'
            - '\repair\system'
            - '\windows\ntds\ntds.dit'
    condition: all of selection_esent_* or selection_susp_paths
falsepositives:
    - Copying sensitive files for legitimate use (eg. backup) or forensic investigation by legitimate incident responder or forensic investigator.
level: high

Stages and Predicates

Stage 0: condition

all of selection_esent_* or selection_susp_paths

Stage 1: selection_esent_img

selection_esent_img:
    - Image|endswith: '\esentutl.exe'
    - OriginalFileName: '\esentutl.exe'

Stage 2: selection_esent_cli

selection_esent_cli:
    CommandLine|contains|windash:
        - 'vss'
        - ' /m '
        - ' /y '

Stage 3: selection_susp_paths

selection_susp_paths:
    CommandLine|contains:
        - '\config\RegBack\sam'
        - '\config\RegBack\security'
        - '\config\RegBack\system'
        - '\config\sam'
        - '\config\security'
        - '\config\system '
        - '\repair\sam'
        - '\repair\security'
        - '\repair\system'
        - '\windows\ntds\ntds.dit'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • /m transforms: windash
  • /y transforms: windash corpus 2 (sigma 2)
  • \config\RegBack\sam
  • \config\RegBack\security
  • \config\RegBack\system
  • \config\sam corpus 4 (sigma 4)
  • \config\security corpus 4 (sigma 4)
  • \config\system
  • \repair\sam
  • \repair\security
  • \repair\system
  • \windows\ntds\ntds.dit corpus 5 (sigma 5)
  • vss transforms: windash corpus 2 (sigma 2)
Imageends_with
  • \esentutl.exe corpus 8 (sigma 8)
OriginalFileNameeq
  • \esentutl.exe