SC-35_external-malicious-code-identification

SC-35 External Malicious Code Identification

High-Level Description

Family: System and Communications Protection (SC) Framework: NIST SP 800-53 Rev 5

External malicious code identification differs from decoys in SC-26 in that the components actively probe networks, including the Internet, in search of malicious code contained on external websites. Like decoys, the use of external malicious code identification techniques requires some supporting isolation measures to ensure that any malicious code discovered during the search and subsequently executed does not infect organizational systems. Virtualization is a common technique for achieving such isolation.

What to Check

• Verify SC-35 External Malicious Code Identification is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for SC-35

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SC-35 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

Include system components that proactively seek to identify network-based malicious code or malicious websites.

Implementation Guidance

External malicious code identification differs from decoys in SC-26 in that the components actively probe networks, including the Internet, in search of malicious code contained on external websites. Like decoys, the use of external malicious code identification techniques requires some supporting isolation measures to ensure that any malicious code discovered during the search and subsequently executed does not infect organizational systems. Virtualization is a common technique for achieving such isolation.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - SC-35
• 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 (SC-7, SC-26, SC-44, SI-3, SI-4) reviewed