Windows Registry Events: Scheduled Task Creation via TaskCache Tree Key

Flags registry activity creating TaskCache Tree entries tied to TeamCity settings UI during exploitation.

FreeReviewedSigma · High · v5

Product: windows
Category: registry_event
Author: Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2023-10-24
Updated: 2026-07-31

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies registry events targeting scheduled task cache entries under the TaskCache Tree path. It looks for a specific value indicative of “Windows TeamCity Settings User Interface,” which can be abused by attackers to establish persistence through scheduled tasks. The detection relies on Windows registry telemetry capturing the TargetObject contents for the relevant TaskCache locations.

Reporting behind it

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Windows Registry Events: Scheduled Task Creation via TaskCache Tree Key

Pivot detection · T1685 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

windows-registry-event-scheduled-taskcache-tree-key-creation-for-teamcity-exploi-9f9f92ba

title: "Windows Registry Events: Scheduled Task Creation via TaskCache Tree Key"
id: d28dea95-48f2-477a-a28e-fdf88d83df2a
status: test
description: This rule identifies registry events targeting scheduled task cache entries under the TaskCache Tree path. It looks for a specific value indicative of “Windows TeamCity Settings User Interface,” which can be abused by attackers to establish persistence through scheduled tasks. The detection relies on Windows registry telemetry capturing the TargetObject contents for the relevant TaskCache locations.
references:
  - https://www.microsoft.com/en-us/security/blog/2023/10/18/multiple-north-korean-threat-actors-exploiting-the-teamcity-cve-2023-42793-vulnerability/
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2023/TA/Diamond-Sleet/registry_event_apt_diamond_sleet_scheduled_task.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2023-10-24
tags:
  - attack.defense-impairment
  - attack.t1685
  - detection.emerging-threats
logsource:
  product: windows
  category: registry_event
detection:
  selection:
    TargetObject|contains|all:
      - \SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\
      - Windows TeamCity Settings User Interface
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: 9f9f92ba-5300-43a4-b435-87d1ee571688
    type: derived

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