Detection rules › Sigma

Deleted Data Overwritten Via Cipher.EXE

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
frack113
Source
github.com/SigmaHQ/sigma

Detects usage of the "cipher" built-in utility in order to overwrite deleted data from disk. Adversaries may destroy data and files on specific systems or in large numbers on a network to interrupt availability to systems, services, and network resources. Data destruction is likely to render stored data irrecoverable by forensic techniques through overwriting files or data on local and remote drives

MITRE ATT&CK coverage

TacticTechniques
ImpactT1485 Data Destruction

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Deleted Data Overwritten Via Cipher.EXE
id: 4b046706-5789-4673-b111-66f25fe99534
status: test
description: |
    Detects usage of the "cipher" built-in utility in order to overwrite deleted data from disk.
    Adversaries may destroy data and files on specific systems or in large numbers on a network to interrupt availability to systems, services, and network resources.
    Data destruction is likely to render stored data irrecoverable by forensic techniques through overwriting files or data on local and remote drives
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1485/T1485.md#atomic-test-3---overwrite-deleted-data-on-c-drive
author: frack113
date: 2021-12-26
modified: 2023-02-21
tags:
    - attack.impact
    - attack.t1485
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'CIPHER.EXE'
        - Image|endswith: '\cipher.exe'
    selection_cli:
        CommandLine|contains: ' /w:'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_cipher_overwrite_deleted_data/info.yml
simulation:
    - type: atomic-red-team
      name: Overwrite deleted data on C drive
      technique: T1485
      atomic_guid: 321fd25e-0007-417f-adec-33232252be19

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_img

selection_img:
    - OriginalFileName: 'CIPHER.EXE'
    - Image|endswith: '\cipher.exe'

Stage 2: selection_cli

selection_cli:
    CommandLine|contains: ' /w:'

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
  • /w:
Imageends_with
  • \cipher.exe corpus 2 (sigma 2)
OriginalFileNameeq
  • CIPHER.EXE