Detection rules › Sigma

NTDS Exfiltration Filename Patterns

Status
test
Severity
high
Log source
category file_event, product windows
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects creation of files with specific name patterns seen used in various tools that export the NTDS.DIT for exfiltration.

MITRE ATT&CK coverage

TacticTechniques
Credential Access

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 11: FileCreate

Rule body

title: NTDS Exfiltration Filename Patterns
id: 3a8da4e0-36c1-40d2-8b29-b3e890d5172a
status: test
description: Detects creation of files with specific name patterns seen used in various tools that export the NTDS.DIT for exfiltration.
references:
    - https://github.com/rapid7/metasploit-framework/blob/eb6535009f5fdafa954525687f09294918b5398d/modules/post/windows/gather/ntds_grabber.rb
    - https://github.com/rapid7/metasploit-framework/blob/eb6535009f5fdafa954525687f09294918b5398d/data/post/powershell/NTDSgrab.ps1
    - https://github.com/SecureAuthCorp/impacket/blob/7d2991d78836b376452ca58b3d14daa61b67cb40/impacket/examples/secretsdump.py#L2405
author: Florian Roth (Nextron Systems)
date: 2022-03-11
modified: 2023-05-05
tags:
    - attack.credential-access
    - attack.t1003.003
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|endswith:
            - '\All.cab' # https://github.com/rapid7/metasploit-framework/blob/eb6535009f5fdafa954525687f09294918b5398d/data/post/powershell/NTDSgrab.ps1
            - '.ntds.cleartext' # https://github.com/SecureAuthCorp/impacket/blob/7d2991d78836b376452ca58b3d14daa61b67cb40/impacket/examples/secretsdump.py#L2405
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetFilename|endswith:
        - '\All.cab'
        - '.ntds.cleartext'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
TargetFilenameends_with
  • .ntds.cleartext
  • \All.cab
field:"TargetFilename" kind:ends_with