Potential SAM Database Dump

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

Detects the creation of files that look like exports of the local SAM (Security Account Manager)

Known false positives

Rare cases of administrative activity

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1003.002` OS Credential Dumping: Security Account Manager

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 11: FileCreate

Rule body

title: Potential SAM Database Dump
id: 4e87b8e2-2ee9-4b2a-a715-4727d297ece0
status: test
description: Detects the creation of files that look like exports of the local SAM (Security Account Manager)
references:
    - https://github.com/search?q=CVE-2021-36934
    - https://web.archive.org/web/20210725081645/https://github.com/cube0x0/CVE-2021-36934
    - https://www.google.com/search?q=%22reg.exe+save%22+sam
    - https://github.com/HuskyHacks/ShadowSteal
    - https://github.com/FireFart/hivenightmare
author: Florian Roth (Nextron Systems)
date: 2022-02-11
modified: 2023-01-05
tags:
    - attack.credential-access
    - attack.t1003.002
logsource:
    product: windows
    category: file_event
detection:
    selection:
        - TargetFilename|endswith:
              - '\Temp\sam'
              - '\sam.sav'
              - '\Intel\sam'
              - '\sam.hive'
              - '\Perflogs\sam'
              - '\ProgramData\sam'
              - '\Users\Public\sam'
              - '\AppData\Local\sam'
              - '\AppData\Roaming\sam'
              - '_ShadowSteal.zip'       # https://github.com/HuskyHacks/ShadowSteal
              - '\Documents\SAM.export'  # https://github.com/n3tsurge/CVE-2021-36934/
              - ':\sam'
        - TargetFilename|contains:
              - '\hive_sam_'             # https://github.com/FireFart/hivenightmare
              - '\sam.save'
              - '\sam.export'
              - '\~reg_sam.save'
              - '\sam_backup'
              - '\sam.bck'
              - '\sam.backup'
    condition: selection
falsepositives:
    - Rare cases of administrative activity
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    - TargetFilename|endswith:
          - '\Temp\sam'
          - '\sam.sav'
          - '\Intel\sam'
          - '\sam.hive'
          - '\Perflogs\sam'
          - '\ProgramData\sam'
          - '\Users\Public\sam'
          - '\AppData\Local\sam'
          - '\AppData\Roaming\sam'
          - '_ShadowSteal.zip'
          - '\Documents\SAM.export'
          - ':\sam'
    - TargetFilename|contains:
          - '\hive_sam_'
          - '\sam.save'
          - '\sam.export'
          - '\~reg_sam.save'
          - '\sam_backup'
          - '\sam.bck'
          - '\sam.backup'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`TargetFilename`	ends_with	`:\sam` `\AppData\Local\sam` `\AppData\Roaming\sam` `\Documents\SAM.export` `\Intel\sam` `\Perflogs\sam` `\ProgramData\sam` `\Temp\sam` `\Users\Public\sam` `\sam.hive` `\sam.sav` `_ShadowSteal.zip`	`field:"TargetFilename" kind:ends_with`
`TargetFilename`	match	`\hive_sam_` corpus 2 (sigma 2) `\sam.backup` `\sam.bck` `\sam.export` `\sam.save` corpus 2 (sigma 2) `\sam_backup` `\~reg_sam.save`	`field:"TargetFilename" kind:match`

Potential SAM Database Dump

Known false positives

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`