Sigma rule: Removal Of Index Value to Hide Schedule Task - Registry

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-515194593314, updated 2025-10-25T00:00:00.000Z.

Rule

Title
Removal Of Index Value to Hide Schedule Task - Registry
Status
test
Level
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Date
2022-08-26
Modified
2025-10-25
File
rules/windows/registry/registry_delete/registry_delete_schtasks_hide_task_via_index_value_removal.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects when the "index" value of a scheduled task is removed or deleted from the registry. Which effectively hides it from any tooling such as "schtasks /query"

Log source

product
windows
category
registry_delete

Detection

selection:
    TargetObject|contains|all:
        - '\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\'
        - 'Index'
condition: selection

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.defense-impairment
  • attack.t1685

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/registry/registry_delete/registry_delete_schtasks_hide_task_via_index_value_removal.yml

Sources and licences

  • SigmaHQ

    "Removal Of Index Value to Hide Schedule Task - Registry" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/registry/registry_delete/registry_delete_schtasks_hide_task_via_index_value_removal.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Removal Of Index Value to Hide Schedule Task - Registry",
entity page, dataset version ref-515194593314, updated 2025-10-25T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/526cc8bc-1cdc-48ad-8b26-f19bff969cec (accessed 2026-11-03).
Underlying source: SigmaHQ rule 526cc8bc-1cdc-48ad-8b26-f19bff969cec, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.