Detection rules › Sigma

PUA - Restic Backup Tool Execution

Status
experimental
Severity
high
Log source
product windows, category process_creation
Author
Nounou Mbeiri, Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the execution of the Restic backup tool, which can be used for data exfiltration. Threat actors may leverage Restic to back up and exfiltrate sensitive data to remote storage locations, including cloud services. If not legitimately used in the enterprise environment, its presence may indicate malicious activity.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: PUA - Restic Backup Tool Execution
id: 6ddff2e8-ea1a-45d0-8938-93dfc1d67ae7
status: experimental
description: |
    Detects the execution of the Restic backup tool, which can be used for data exfiltration.
    Threat actors may leverage Restic to back up and exfiltrate sensitive data to remote storage locations, including cloud services.
    If not legitimately used in the enterprise environment, its presence may indicate malicious activity.
references:
    - https://thedfirreport.com/2024/09/30/nitrogen-campaign-drops-sliver-and-ends-with-blackcat-ransomware/#exfiltration
    - https://restic.net/
    - https://restic.readthedocs.io/en/stable/030_preparing_a_new_repo.html
author: Nounou Mbeiri, Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-10-17
tags:
    - attack.exfiltration
    - attack.t1048
    - attack.t1567.002
logsource:
    product: windows
    category: process_creation
detection:
    selection_specific:
        - CommandLine|contains|all:
              - '--password-file'
              - 'init'
              - ' -r '
        - CommandLine|contains|all:
              - '--use-fs-snapshot'
              - 'backup'
              - ' -r '
    selection_restic:
        CommandLine|contains:
            - 'sftp:'
            - 'rest:http'
            - 's3:s3.'
            - 's3.http'
            - 'azure:'
            - ' gs:'
            - 'rclone:'
            - 'swift:'
            - ' b2:'
        CommandLine|contains|all:
            - ' init '
            - ' -r '
    condition: 1 of selection_*
falsepositives:
    - Legitimate use of Restic for backup purposes within the organization.
level: high

Stages and Predicates

Stage 0: condition

1 of selection_*

Stage 1: selection_specific

selection_specific:
    - CommandLine|contains|all:
          - '--password-file'
          - 'init'
          - ' -r '
    - CommandLine|contains|all:
          - '--use-fs-snapshot'
          - 'backup'
          - ' -r '

Stage 2: selection_restic

selection_restic:
    CommandLine|contains:
        - 'sftp:'
        - 'rest:http'
        - 's3:s3.'
        - 's3.http'
        - 'azure:'
        - ' gs:'
        - 'rclone:'
        - 'swift:'
        - ' b2:'
    CommandLine|contains|all:
        - ' init '
        - ' -r '

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
  • -r corpus 10 (sigma 10)
  • b2:
  • gs:
  • init
  • --password-file
  • --use-fs-snapshot
  • azure:
  • backup corpus 6 (sigma 5, splunk 1)
  • init
  • rclone:
  • rest:http
  • s3.http
  • s3:s3.
  • sftp:
  • swift: