AN0840: Analytic 0840
Suspicious calls to dlopen(), dlsym(), or mmap with RWX flags in processes that do not typically perform dynamic module loading. Monitor anonymous memory regions executed by user processes.
Analyst context for executives and security teams
This analytic is relevant to macOS environments because it focuses on behavior that can indicate unusual in-memory code loading: calls to dlopen(), dlsym(), or mmap with read-write-execute permissions, especially in processes that do not normally load dynamic modules. For leaders, the value is not that this proves malicious activity, but that it tests whether the organization can see suspicious runtime behavior that may not leave a simple file-based indicator.
Executive priority
Prioritize this as a visibility and response-readiness question for macOS fleets: do SOC and IR teams have the telemetry needed to distinguish expected application behavior from suspicious dynamic loading or executable anonymous memory? This supports control prioritization around endpoint monitoring, audit evidence for detection capability, and incident decision-making when file, hash, or signature-based evidence is insufficient.
Technical view
For macOS detection engineering, validate whether endpoint telemetry can observe user processes calling dlopen(), dlsym(), and mmap, including mmap events that create RWX memory regions. Baseline which processes normally perform dynamic module loading, then focus review on processes where that behavior is atypical. Because the ATT&CK object provides no tactic mapping, relationships, or formal detection logic, teams should treat this as an analytic concept requiring local baselining, tuning, and validation rather than a ready-to-deploy rule.
Likely telemetry
- macOS endpoint process telemetry
- API or system call monitoring for dlopen(), dlsym(), and mmap
- Memory protection attributes, especially RWX mappings
- Evidence of anonymous memory regions later executed by user processes
- Process identity, parent process, command line, signing/notarization context where available
Detection direction
- Confirm telemetry can capture dynamic loading and memory mapping behavior on macOS, not just process creation and file events.
- Build baselines for processes that legitimately use dlopen(), dlsym(), or executable memory to reduce false positives.
- Prioritize alerts where dynamic module loading occurs in processes that do not typically perform it, as stated by the analytic.
- Review anonymous executable memory regions created or executed by user processes, especially when paired with unusual process lineage or unsigned/unexpected code context.
- Document blind spots where endpoint tooling cannot observe API calls, memory permissions, or anonymous executable regions.
Mitigation priorities
- Start with visibility: ensure macOS endpoint monitoring can collect the evidence classes required by the analytic.
- Define normal dynamic-loading behavior for important business applications and high-value user groups.
- Use least-privilege, application control, and endpoint hardening practices where appropriate to reduce opportunities for unapproved code execution.
- Prepare IR procedures for collecting process, memory, and module-loading evidence when this behavior is observed.
- Use detection validation results as compliance and resilience evidence, while noting that this analytic alone does not prove malicious activity.
Analyst notes and limits
The supplied ATT&CK object is a detection analytic for macOS only. It describes suspicious use of dlopen(), dlsym(), and mmap with RWX flags, plus monitoring anonymous executable memory regions. No tactic, technique relationship, detection implementation, or adversary relationship was supplied, so the take emphasizes validation and operational use rather than attribution or coverage claims.
Official detection content is not provided, and no relationships are supplied. This limits precision around ATT&CK tactic context, expected adversary behavior, and rule logic. Local macOS application baselines and endpoint telemetry capabilities are required before this can be converted into reliable production detection.
Analytic 0840
Suspicious calls to dlopen(), dlsym(), or mmap with RWX flags in processes that do not typically perform dynamic module loading. Monitor anonymous memory regions executed by user 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 | 459a3e962a72… |
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.
-
[1]
mitre-attack AN0840Open source URL
Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.