EvidenceSheet
NIST SP 800-53 Rev 5 · SI - System and Information Integrity

SI-4(11) System Monitoring | Analyze Communications Traffic Anomalies

Analyze outbound communications traffic at the external interfaces to the system and selected organization-defined interior points within the system to discover anomalies.

Source: NIST SP 800-53 Rev 5, SI-4(11). The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open NIST SP 800-53 Rev 5 in the compliance library.

Base controls and their enhancements. Which apply follows the baseline you are assessed against (for example FedRAMP Moderate or High, or the low, moderate and high baselines of SP 800-53B). Text in square brackets is a parameter your organisation sets.

10
artefacts
1
held by a system
2
at each review
hard
to go live
Policy repository / GRC workspace
where the evidence lives
teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

  • System monitoring logs or records · SIEM / log platform

periodic reviewEvidence produced at each review

  • System audit records · Policy repository / GRC workspace
  • Test of Organizational processes for intrusion detection and system monitoring; mechanisms supporting and/or implementing intrusion detection and system monitoring capabilities; mechanisms supporting and/or implementing the analysis of communications traffic · SIEM / log platform

governing documentDocuments that govern the control

  • System and information integrity policy · Policy repository / GRC workspace
  • System and information integrity procedures · Policy repository / GRC workspace
  • Procedures addressing system monitoring tools and techniques · Policy repository / GRC workspace
  • System design documentation · Document repository
  • Network diagram · Policy repository / GRC workspace
  • System monitoring tools and techniques documentation · Policy repository / GRC workspace
  • System configuration settings and associated documentation · Policy repository / GRC workspace

First move

Mostly documents and reviews. Pull the 1 system-held artefact from your SIEM / log platform on a schedule; put the documents under version control with an owner and review date, and log each review as a dated record with a named reviewer.

Common gaps auditors find

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

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SI-4(10) System Monitoring | Visibility of Encrypted Communications · SI-4(12) System Monitoring | Automated Organization-generated Alerts