AN0243: Analytic 0243
Monitors suspicious usage of Windows API calls like SetWindowsHookEx, GetKeyState, or polling functions within non-UI service processes, combined with Registry or driver modifications.
Analyst context for executives and security teams
AN0243 is a Windows detection analytic focused on unusual service-process behavior: non-UI services using input-related Windows APIs such as SetWindowsHookEx, GetKeyState, or polling functions, especially when paired with Registry or driver changes. For leaders, the value is not the API names themselves; it is whether the organization can recognize when background services start behaving like interactive user-monitoring components while also changing persistence-sensitive system areas.
Executive priority
Prioritize this as an endpoint visibility and change-control validation item for Windows environments. It can inform whether SOC and IR teams have enough evidence to investigate suspicious service behavior, Registry modification, and driver modification together rather than as isolated alerts. It is also useful for audit and resilience discussions because the analytic depends on proving that endpoint telemetry, service governance, and privileged system-change monitoring are actually in place.
Technical view
Validate whether Windows endpoint telemetry can identify API usage by process context, distinguish non-UI service processes from normal interactive applications, and correlate that activity with Registry or driver modifications. Because no ATT&CK tactic, relationship context, or official detection logic is supplied, teams should treat this as a detection-engineering pattern rather than a complete rule. Tuning should focus on known legitimate services that use UI hooks or polling functions, approved driver activity, and authorized Registry changes.
Likely telemetry
- Windows endpoint process telemetry, including process name, path, parent process, service context, user account, and session/desktop context
- API-call or behavioral telemetry showing use of SetWindowsHookEx, GetKeyState, or polling-style input functions
- Registry modification events, including key path, value name, process responsible, and user/service account
- Driver modification or driver load/install events, including file path, signer, hash, and initiating process
- Service inventory and service configuration data to identify non-UI service processes and expected behavior
Detection direction
- Confirm the SOC can correlate suspicious input-related API use with Registry or driver modifications within a useful investigation window.
- Tune out approved software and services that legitimately use UI hooks, polling, Registry updates, or driver maintenance to reduce false positives.
- Pay attention to process context: the analytic is specifically stronger when the behavior occurs in non-UI service processes, not ordinary interactive applications.
- Validate telemetry depth before writing high-severity logic; many environments collect process and Registry data but not detailed API-call telemetry.
- Use driver and Registry change context as corroborating evidence rather than relying on a single API call event.
Mitigation priorities
- Maintain an inventory of legitimate Windows services and expected service behaviors, including any approved UI interaction or driver activity.
- Apply change control and monitoring for Registry and driver modifications, especially when initiated by service processes.
- Limit unnecessary service privileges and review service accounts that can modify sensitive system areas.
- Ensure endpoint monitoring covers Windows service context, Registry changes, and driver changes before depending on this analytic for incident response decisions.
- Document approved exceptions so detection tuning can separate administrative or software-maintenance activity from suspicious service behavior.
Analyst notes and limits
This take is based only on the supplied MITRE analytic AN0243 fields. The object provides a concise description but no official detection logic, no ATT&CK tactics, and no relationship context. Local baselining is required to determine which services legitimately use the referenced APIs or perform Registry and driver modifications.
The supplied object does not provide adversary relationships, procedure examples, severity, active exploitation evidence, or a complete analytic query. Coverage depends on the organization’s Windows endpoint telemetry depth, especially API-call visibility and correlation with Registry and driver events.
Analytic 0243
Monitors suspicious usage of Windows API calls like SetWindowsHookEx, GetKeyState, or polling functions within non-UI service processes, combined with Registry or driver modifications.
How security teams should use this page
Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.
All related ATT&CK context
No relationships are available in the current normalized data for this object.
Object version and sync metadata
The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates .
Imported snapshots across ATT&CK releases (1)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.1 | 1.0 | Current bundle | fba650ba950c… |
Mirrored ATT&CK source object
The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
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mitre-attack AN0243Open source URL
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