AT-3(4)_suspicious-communications-and-anomalous-system-behavior

Imported from CyberStrikeus/CyberStrike (.cyberstrike/skill/NIST/SP800-53_rev5/AT_awareness-and-training/at-3-4-suspicious-communications-and/SKILL.md). Install upstream with npx skills add CyberStrikeus/CyberStrike --skill at-3-4-suspicious-communications-and. Copyright stays with the author.

AT-3(4) Suspicious Communications and Anomalous System Behavior

Enhancement of: AT-3

High-Level Description

Family: Awareness and Training (AT) Framework: NIST SP 800-53 Rev 5

No description available.

What to Check

• Verify AT-3(4) Suspicious Communications and Anomalous System Behavior is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for AT-3(4)
• Verify enhancement builds upon base control AT-3

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for AT-3(4) implementation details. Verify the organization has documented how this control is satisfied.

Step 2: Validate Implementation

# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null

Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

Tools

Remediation Guide

Control Statement

Refer to NIST SP 800-53 Rev 5 for the full control statement.

Implementation Guidance

Implement this control per organizational risk assessment and system categorization.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - AT-3(4)
• NIST SP 800-53A Rev 5 (Assessment Procedures)
• NIST SP 800-53 Rev 5 Full Catalog

Checklist

• Control documented in SSP
• Implementation evidence collected
• Operating effectiveness validated
• Continuous monitoring in place
• Related controls (none) reviewed