Detection rules › Sigma

Delete All Scheduled Tasks

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the usage of schtasks with the delete flag and the asterisk symbol to delete all tasks from the schedule of the local computer, including tasks scheduled by other users.

MITRE ATT&CK coverage

TacticTechniques
ImpactT1489 Service Stop

Event coverage

Rule body yaml

title: Delete All Scheduled Tasks
id: 220457c1-1c9f-4c2e-afe6-9598926222c1
status: test
description: Detects the usage of schtasks with the delete flag and the asterisk symbol to delete all tasks from the schedule of the local computer, including tasks scheduled by other users.
references:
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/schtasks-delete
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-09
tags:
    - attack.impact
    - attack.t1489
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\schtasks.exe'
        CommandLine|contains|all:
            - ' /delete '
            - '/tn \*'
            - ' /f'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '\schtasks.exe'
    CommandLine|contains|all:
        - ' /delete '
        - '/tn \*'
        - ' /f'

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
  • /delete corpus 2 (sigma 2)
  • /f corpus 3 (sigma 2, chronicle 1)
  • /tn \*
Imageends_with
  • \schtasks.exe corpus 56 (sigma 56)