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AT-3(4) Awareness and Training

Suspicious Communications and Anomalous System Behavior

High Risk Moderate Medium Cost

AT-3(4) (Suspicious Communications and Anomalous System Behavior) enhances base AT-3 within the NIST Awareness and Training family. Base AT-3 sets the foundational expectation; this enhancement adds specificity: This enhancement strengthens AT-3 with requirements for suspicious communications and anomalous system behavior in environments that create, receive, maintain, or transmit ePHI. Covered entities and business associates apply it to role-based security awareness and specialized training for clinicians, IT, and privacy staff handling ePHI.

Control Objective

Implement Suspicious Communications and Anomalous System Behavior so organization-defined awareness and training safeguards operate consistently on systems and networks that handle ePHI, with measurable evidence for HIPAA and NIST assessments.

Implementation Guidance

  1. Map AT-3(4) to systems in scope (EHR, imaging, lab, pharmacy, billing, identity, backups, and BA connections).\n2. Translate “Suspicious Communications and Anomalous System Behavior” into technical settings, procedures, or architecture patterns owned by named roles.\n3. Prefer enforceable controls (config, automation, mediation) over awareness-only measures where feasible.\n4. Integrate with change, incident, and downtime processes so clinical operations are not surprised.\n5. Log and retain evidence of operation (tickets, configs, test results) aligned to audit needs.\n6. Include vendors/BAs in contracts and connection standards when they touch the control surface.\n7. Test after major EHR, network, or cloud changes — upgrades often reset protections.\n8. Review exceptions at least quarterly; expire “temporary” holes that expose ePHI paths.

Real-World Use Cases

How this control shows up in healthcare and HIPAA-covered environments.

Real-world scenario

Privileged admin role training (AT-3(4))\nEHR security analysts complete role-based modules on change control and audit abuse. Evidence labeled for AT-3(4).\n\n### Environmental/physical for facilities (AT-3(4))\nFacilities staff supporting computer rooms train on PE controls that protect ePHI systems. Evidence labeled for AT-3(4).\n\n### Suspicious communications module (AT-3(4))\nHelpdesk learns to spot anomalous reset requests targeting accounts with chart access. Evidence labeled for AT-3(4).

Best Practices

  • Name an owner for AT-3(4) in the SSP control matrix.\n- Favor system enforcement on ePHI paths over informal email approval.\n- Measure coverage: percent of in-scope clinical systems where the enhancement operates.\n- Review exceptions quarterly with security and clinical informatics.\n- Feed relevant events to SIEM with a named use case.\n- Keep a one-page evidence pack (config + sample log + last test) ready for assessors.

Common Gaps & Violations

  • Policy cites AT-3(4) but production EHR/network paths show no enforcement of suspicious communications and anomalous system behavior.\n- Permanent exceptions with no expiry for vendors or “special” clinics.\n- Control implemented only on corporate IT — clinical devices and interfaces omitted.\n- No logs or test records; reliance on tribal knowledge.\n- Major upgrade silently disabled the enhancement.

Required Documentation

  • Procedure/standard for Suspicious Communications and Anomalous System Behavior (AT-3(4))\n- Architecture or configuration baselines showing enforcement points\n- Exception register with owners and expiry\n- Sample logs, alerts, or test results\n- Training or runbook references for clinical/IT operators

How to Test & Validate

  1. Attempt a prohibited or out-of-policy action related to suspicious communications and anomalous system behavior; confirm block, alert, or required workflow.\n2. Complete an authorized clinical/IT path; confirm success and logging.\n3. Sample open exceptions for approval and expiry.\n4. Verify at least one EHR-adjacent and one BA/vendor path are in scope.\n5. Confirm evidence retained for the last 90 days (or per policy).

Audit Considerations

Assessors look for operating evidence of Suspicious Communications and Anomalous System Behavior on systems touching ePHI — configs, logs, restore/DR artifacts, or failed-test results — not only a policy paragraph referencing AT-3(4).

HIPAA Mapping

How this NIST control supports HIPAA Security Rule expectations.

  • 164.308(a)(5)(i) Security Awareness and Training — train workforce on security for ePHI.\n- 164.308(a)(5)(ii)(A) Security Reminders — periodic security updates.\n- 164.308(a)(5)(ii)(B) Protection from Malicious Software — training on malware threats.\n- 164.308(a)(5)(ii)(D) Password Management — training on creating and changing passwords.

Compliance Tips

  • List AT-3(4) explicitly in the system security plan with system inventory references.\n- Prioritize emergency department, inpatient EHR, and remote access paths first.\n- Bundle evidence with related HIPAA evaluation, integrity, or workforce-security narratives where they overlap.

References & Resources

  • NIST SP 800-53 Rev. 5 — AT-3(4)\n- Related controls: AT-3, AT-2(4)

Related Guidelines

Related controls that commonly accompany AT-3(4).

AT-3 Medium

Role-Based Security Training

AT-3 requires providing role-based security training to personnel with assigned security roles and responsibilities before authorizing…
AT-1 Medium

Security Awareness and Training Policy and Procedures

AT-1 requires an awareness and training policy and procedures addressing purpose, scope, roles, management commitment, coordination, and…
AT-2 Medium

Security Awareness Training

AT-2 requires providing basic security awareness training to system users as part of initial training, when required by information system…

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