Detection rules › Sigma
Fsutil Suspicious Invocation
Detects suspicious parameters of fsutil (deleting USN journal, configuring it with small size, etc). Might be used by ransomwares during the attack (seen by NotPetya and others).
Known false positives
- Admin activity
- Scripts and administrative tools used in the monitored environment
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | |
| Impact |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
title: Fsutil Suspicious Invocation
id: add64136-62e5-48ea-807e-88638d02df1e
status: stable
description: |
Detects suspicious parameters of fsutil (deleting USN journal, configuring it with small size, etc).
Might be used by ransomwares during the attack (seen by NotPetya and others).
references:
- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/fsutil-usn
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070/T1070.md
- https://eqllib.readthedocs.io/en/latest/analytics/c91f422a-5214-4b17-8664-c5fcf115c0a2.html
- https://github.com/albertzsigovits/malware-notes/blob/558898932c1579ff589290092a2c8febefc3a4c9/Ransomware/Lockbit.md
- https://blog.cluster25.duskrise.com/2023/05/22/back-in-black-blackbyte-nt
author: Ecco, E.M. Anhaus, oscd.community
date: 2019-09-26
modified: 2023-09-09
tags:
- attack.impact
- attack.stealth
- attack.t1070
- attack.t1485
logsource:
category: process_creation
product: windows
detection:
selection_img:
- Image|endswith: '\fsutil.exe'
- OriginalFileName: 'fsutil.exe'
selection_cli:
CommandLine|contains:
- 'deletejournal' # usn deletejournal ==> generally ransomware or attacker
- 'createjournal' # usn createjournal ==> can modify config to set it to a tiny size
- 'setZeroData' # file setZeroData ==> empties a file with zeroes
condition: all of selection_*
falsepositives:
- Admin activity
- Scripts and administrative tools used in the monitored environment
level: high
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
- Image|endswith: '\fsutil.exe'
- OriginalFileName: 'fsutil.exe'
Stage 2: selection_cli
selection_cli:
CommandLine|contains:
- 'deletejournal'
- 'createjournal'
- 'setZeroData'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
Image | ends_with |
| field:"Image" kind:ends_with value:"\fsutil.exe" |
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"fsutil.exe" |