{"id":"acd74772-5f88-45c7-956b-6a7b36c294d2","title":"Removal Of SD Value to Hide Schedule Task - Registry","description":"Remove SD (Security Descriptor) value in \\Schedule\\TaskCache\\Tree registry hive to hide schedule task. This technique is used by Tarrask malware","author":"Sittikorn S","status":"test","level":"medium","date":"2022-04-15","modified":"2025-10-25","tags":["attack.defense-impairment","attack.t1685"],"technique_ids":["T1685"],"logsource":{"product":"windows","category":"registry_delete"},"falsepositives":["Unknown"],"references":["https://www.microsoft.com/security/blog/2022/04/12/tarrask-malware-uses-scheduled-tasks-for-defense-evasion/"],"source_path":"rules/windows/registry/registry_delete/registry_delete_schtasks_hide_task_via_sd_value_removal.yml","source_sha256":"f58cd85f440f172074572f9c6e6454d954210aa6c15b01c1f45ccda6fcb8f7e4","source_url":"https://github.com/anpa1200/sigma/blob/b249e9683190cffdcaf188ccbfb90bf4759844e1/rules/windows/registry/registry_delete/registry_delete_schtasks_hide_task_via_sd_value_removal.yml","license":"Detection Rule License 1.1","license_url":"https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md","yaml":"title: Removal Of SD Value to Hide Schedule Task - Registry\nid: acd74772-5f88-45c7-956b-6a7b36c294d2\nrelated:\n    - id: 526cc8bc-1cdc-48ad-8b26-f19bff969cec\n      type: similar\nstatus: test\ndescription: Remove SD (Security Descriptor) value in \\Schedule\\TaskCache\\Tree registry hive to hide schedule task. This technique is used by Tarrask malware\nreferences:\n    - https://www.microsoft.com/security/blog/2022/04/12/tarrask-malware-uses-scheduled-tasks-for-defense-evasion/\nauthor: Sittikorn S\ndate: 2022-04-15\nmodified: 2025-10-25\ntags:\n    - attack.defense-impairment\n    - attack.t1685\nlogsource:\n    product: windows\n    category: registry_delete\ndetection:\n    selection:\n        TargetObject|contains|all:\n            - '\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Schedule\\TaskCache\\Tree\\'\n            - 'SD'\n    condition: selection\nfalsepositives:\n    - Unknown\nlevel: medium\nregression_tests_path: regression_data/rules/windows/registry/registry_delete/registry_delete_schtasks_hide_task_via_sd_value_removal/info.yml\n","validation":"yaml_parsed_not_backend_compiled_or_live_validated","techniques":[{"key":"enterprise/T1685","id":"T1685","name":"Disable or Modify Tools","page":"techniques/enterprise/T1685/"}],"data_path":"data/detection-rules/acd74772-5f88-45c7-956b-6a7b36c294d2.json","kind":"sigma"}