AN0552: Analytic 0552
Alterations to plist configuration files (RulesActiveState.plist, SyncedRules.plist, UnsyncedRules.plist, MessageRules.plist) that define email hiding or filtering rules. Defender perspective: unexpected changes in these files associated with Mail.app processes.
Analyst context for executives and security teams
AN0552 is a macOS detection analytic focused on unexpected changes to Mail.app plist rule files that can hide or filter email. For security leaders, the practical issue is not the plist files themselves, but whether business-critical email evidence, user visibility, and incident communications could be silently altered on endpoints. This matters for executive assurance because mail-rule manipulation can undermine investigations, compliance evidence, and user awareness if endpoint and file-change telemetry is not collected.
Executive priority
Prioritize validation where macOS endpoints and Apple Mail are in scope for executives, administrators, legal, finance, or other sensitive users. Leaders should ask whether the SOC can prove when Mail.app rule configuration files changed, which process changed them, and whether those changes were expected. This analytic is most useful as an endpoint integrity and incident-response readiness control rather than a standalone business-risk conclusion.
Technical view
The supplied analytic applies to macOS and looks for alterations to plist configuration files associated with Mail.app rules: RulesActiveState.plist, SyncedRules.plist, UnsyncedRules.plist, and MessageRules.plist. SOC and detection engineering teams should validate file modification monitoring for these paths and correlate changes with Mail.app-related processes. Because no ATT&CK tactic, technique relationship, or official detection logic was supplied, implementation should be treated as a hypothesis requiring local baselining and testing.
Likely telemetry
- macOS file creation, modification, and deletion events for Mail.app rule plist files
- Process execution and process-to-file activity showing which process modified the plist files
- Endpoint detection and response telemetry from macOS hosts
- File metadata such as path, timestamp, owner, hash, and permissions
- User and device context for the macOS account where Mail.app rules changed
Detection direction
- Confirm the organization collects macOS file-change telemetry for RulesActiveState.plist, SyncedRules.plist, UnsyncedRules.plist, and MessageRules.plist.
- Correlate plist changes with Mail.app processes and flag unexpected or non-standard process associations.
- Baseline legitimate user-driven Mail.app rule changes to reduce false positives.
- Prioritize alerts for sensitive users or systems where hidden or filtered email could affect incident response, approvals, legal holds, or compliance evidence.
- Document blind spots where macOS endpoint telemetry, file integrity monitoring, or Apple Mail usage visibility is absent.
Mitigation priorities
- Establish endpoint telemetry coverage for managed macOS systems before relying on this analytic operationally.
- Restrict and monitor administrative access on macOS endpoints where feasible.
- Use endpoint management and configuration controls to maintain visibility into Apple Mail configuration changes on in-scope devices.
- Define incident-response procedures for reviewing unexpected Mail.app rule changes and preserving relevant plist evidence.
- Include this control in compliance or audit evidence only after confirming collection, retention, and alert review processes.
Analyst notes and limits
This is a detection analytic object, not a full ATT&CK technique description. The official description is specific to macOS Mail.app plist files and unexpected changes associated with Mail.app processes. No relationship context was supplied, so this take avoids mapping the behavior to a tactic, technique, threat actor, campaign, or impact scenario beyond the stated file-change behavior.
Official detection logic was not provided, and no relationships were supplied. Local environment evidence is required to determine exact file paths, normal Mail.app rule-change patterns, telemetry availability, false-positive rates, and response procedures. This summary does not claim active exploitation, attribution, or guaranteed detection coverage.
Analytic 0552
Alterations to plist configuration files (RulesActiveState.plist, SyncedRules.plist, UnsyncedRules.plist, MessageRules.plist) that define email hiding or filtering rules. Defender perspective: unexpected changes in these files associated with Mail.app processes.
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 | ca45b0b1be2d… |
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 AN0552Open source URL
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