SI-4: System Monitoring

To meet the si-4: system monitoring requirement, you must continuously monitor your systems for indicators of compromise and policy violations, generate actionable alerts, and prove the monitoring is operating through repeatable evidence. Operationalize SI-4 by defining monitored assets and events, centralizing telemetry, tuning detections, running a triage workflow, and retaining logs, alerts, and response records. ¹

Key takeaways:

• Define monitoring scope first (systems, users, network paths, and cloud services), then map telemetry to detections and response.
• Evidence matters as much as tooling: keep log coverage maps, alert metrics, triage records, and tuning change logs.
• Assign a control owner and a recurring evidence cadence so SI-4 survives staffing and tooling changes.

SI-4 is where “security monitoring” stops being an aspiration and becomes an auditable control. A CCO or GRC lead usually inherits a mix of tools (EDR, SIEM, cloud logs) and informal practices (someone checks dashboards “when there’s time”). SI-4 forces you to formalize that into a defined monitoring program: what you monitor, what you detect, who responds, and what proof you keep.

For federal information systems and contractors handling federal data, SI-4 typically becomes the backbone control that supports incident detection, incident response, and ongoing assurance. If you cannot show consistent monitoring coverage and an operating workflow, assessors will treat related controls as suspect even if you own strong security tools. The fastest path to readiness is not buying more technology; it’s building a clean control narrative, a scope-backed telemetry plan, and a small set of evidence artifacts you can reproduce on demand.

This page gives requirement-level guidance you can implement quickly: scoping, technical and operational steps, audit-ready evidence, common pitfalls, and a practical execution plan. ¹

Regulatory text

NIST excerpt: “Monitor the system to detect:” ²

Operator meaning: You must run monitoring that can detect adverse events in the environment. For audit and assessment, “monitor” has to be demonstrable: defined scope, configured telemetry sources, documented detection logic (even if vendor-provided), alerting routes, triage actions, and retained records that show the process runs consistently. ¹

Plain-English interpretation (what SI-4 is asking for)

SI-4 expects you to:

1. Collect security-relevant telemetry from endpoints, servers, network devices, identity systems, and cloud control planes that are in scope.
2. Detect suspicious or policy-violating activity using rules, analytics, signatures, and/or vendor detections.
3. Alert the right people with enough context to act.
4. Triage and respond via a defined workflow (even if response lives in a separate incident process).
5. Prove it’s operating with repeatable evidence.

A practical test: if an assessor asks “show me what your monitoring would catch and what happens next,” you should be able to walk from asset → log source → detection → alert → ticket → disposition in a single thread.

Who SI-4 applies to

Entity types (typical applicability):

• Federal information systems
• Contractor systems handling federal data ²

Operational contexts where SI-4 becomes high scrutiny:

• Systems processing regulated or mission-impacting data
• Hybrid environments (on-prem + cloud) where logging is fragmented
• High-change orgs (CI/CD, frequent releases) where detections need tuning
• Third-party dependencies where telemetry is partially outside your control (managed service providers, SaaS)

What you actually need to do (step-by-step)

Step 1: Assign ownership and define “monitoring scope”

Create a short SI-4 control record that names:

• Control owner (Security Operations, IT Security, or a delegated MSSP owner)
• In-scope systems (production first; include supporting identity and admin systems)
• Monitoring objectives (detect compromise, misuse, and policy violations)

Deliverable: “SI-4 Control Implementation Summary” with scope statement and owner.

Step 2: Build a log/telemetry coverage map

List your in-scope assets and the telemetry you collect for each. Keep it simple and auditable.

Minimum fields to track:

• Asset category (endpoint/server/network/cloud/identity/app)
• Data source (EDR agent, syslog, cloud audit logs, IdP logs)
• Collection method (agent, API, forwarder)
• Central destination (SIEM, data lake, managed SOC portal)
• Retention owner (who can produce historical logs)
• Known gaps and compensating controls

This artifact prevents the most common SI-4 failure: “We have a SIEM” but cannot show what is actually feeding it.

Step 3: Define “detectable events” and map to detections

Convert monitoring objectives into a detection catalog. You do not need to publish sensitive rule logic in a GRC tool; you do need a mapping from threat/event type to detection capability and response route.

Examples of event classes most teams map:

• Authentication anomalies (impossible travel, brute force indicators)
• Privileged activity (new admin accounts, role escalations)
• Endpoint compromise indicators (malware, suspicious persistence)
• Network indicators (unexpected egress, beaconing patterns)
• Cloud control plane changes (security group changes, audit log disablement)
• Log pipeline failures (collector down, ingestion drops)

For each class, document:

• Detection source(s)
• Alert destination (SOC queue, ticketing system)
• Triage playbook reference (even a one-page SOP)

Step 4: Implement alert routing and a triage workflow that produces records

Monitoring without triage is noise. Define:

• Intake channel (SIEM queue, MSSP portal, ticketing system)
• Severity model (simple is fine: low/medium/high/critical)
• Triage steps (validate, scope impact, contain/escalate)
• Escalation path (IR team, IT, cloud team, legal/privacy as needed)
• Closure requirements (disposition + rationale)

Evidence must show real operation: alerts created, tickets opened, decisions recorded, and closures tracked.

Step 5: Tune detections and control changes

Assessors expect you to manage false positives and environment changes. Keep:

• A detection tuning log (rule enabled/disabled, thresholds changed, rationale)
• Change approvals for high-impact monitoring changes (new collector, retention change, disabling a major alert)
• Periodic review notes (which detections are noisy, which gaps are being closed)

Step 6: Test monitoring end-to-end

Run controlled tests that create expected telemetry and confirm:

• The event is logged
• The detection fires
• The alert reaches the triage queue
• A ticket is created and closed with a disposition

Keep the test evidence (screenshots, tickets, and a short test memo). This becomes your best audit artifact because it proves the whole chain.

Step 7: Operationalize with a recurring evidence cadence

SI-4 commonly fails on evidence drift. Put recurring tasks on a calendar:

• Review log source health and ingestion failures
• Review alert queues and aging
• Review detection tuning changes
• Review monitoring scope changes (new cloud accounts, new apps)

Daydream fit (earned mention): if you struggle to keep SI-4 evidence consistent across teams and tools, Daydream can act as the control system of record, tying SI-4 to an owner, an implementation procedure, and a recurring evidence checklist so audits become evidence retrieval, not archaeology. ²

Required evidence and artifacts to retain (audit-ready)

Use a simple evidence register. Common SI-4 artifacts:

• SI-4 control narrative (owner, scope, toolchain, workflow)
• Asset-to-telemetry coverage map with noted gaps and dates
• Log source configuration evidence (collector configs, cloud logging enabled screenshots/exports)
• Detection catalog (event class → detection name/source → routing)
• Alert samples (sanitized) showing timestamps and context
• Ticket/Case records showing triage, escalation, and closure
• Monitoring health reports (ingestion status, collector uptime, failed sources list)
• Retention configuration (log retention settings and access controls)
• Tuning/change log for detections and monitoring pipeline changes
• Tabletop or functional test results proving end-to-end detection and alerting

Common exam/audit questions and hangups

Expect these questions:

• “Show which systems are monitored and how you know coverage is complete.”
• “Show me alerts from the last period and the tickets they generated.”
• “How do you detect when logging is disabled or ingestion fails?”
• “Who reviews alerts, and what is the escalation path?”
• “How do you handle monitoring for cloud and SaaS where you don’t control the host?”
• “How do you tune detections and approve disabling noisy rules?”

Hangups that cause findings:

• No single artifact proves scope-to-telemetry completeness.
• Alerts exist, but triage decisions are in chat and not retained.
• Logging is enabled, but ingestion failures are not monitored.
• Monitoring exists only for part of the environment (for example, endpoints but not identity/cloud control plane).

Frequent implementation mistakes (and how to avoid them)

1. Tool-first, scope-last. Fix: write the scope statement and coverage map before you argue tool efficacy.
2. No proof of operation. Fix: keep ticket evidence and end-to-end monitoring tests.
3. Alert fatigue with no tuning discipline. Fix: require a change log entry for material tuning decisions.
4. Blind spots in identity and cloud control plane. Fix: treat IdP and cloud audit logs as first-class sources in the coverage map.
5. Outsourced SOC with weak accountability. Fix: document who owns SI-4, what the MSSP does, and how you receive reports and case records.

Enforcement context and risk implications

Public enforcement materials were not provided in the source catalog for this requirement, so this page does not cite specific SI-4 enforcement actions. Practically, SI-4 gaps increase the likelihood that intrusions persist longer, logs are unavailable during investigations, and incident disclosures become harder to substantiate. That combination tends to elevate regulatory, contractual, and litigation risk even where SI-4 is “only” a framework expectation. ¹

Practical 30/60/90-day execution plan

Days 0–30: Establish the auditable baseline

• Assign SI-4 owner and publish a one-page control narrative.
• Inventory in-scope systems and create the telemetry coverage map.
• Confirm central log destination(s) and access paths for evidence retrieval.
• Define the triage workflow and ensure it produces tickets/case records.

Days 31–60: Close the biggest detection and evidence gaps

• Add missing high-value sources (identity logs, cloud audit logs, critical servers).
• Publish a detection catalog mapped to your main event classes.
• Implement monitoring for log pipeline failures (collector/ingestion alerts).
• Start a tuning/change log and require entries for material changes.

Days 61–90: Prove effectiveness and make it repeatable

• Run end-to-end monitoring tests and retain results.
• Produce an evidence pack for the period: alerts, tickets, health reports, tuning log.
• Add a recurring review cadence (coverage, ingestion health, alert aging, tuning).
• If evidence collection is still manual and fragile, centralize it in Daydream as the system of record for SI-4 ownership, procedures, and recurring artifacts. ²

Frequently Asked Questions

Does SI-4 require a SIEM?

SI-4 requires monitoring that can detect adverse events and produce evidence of operation. A SIEM is a common way to centralize telemetry and alerts, but the control can be met with other architectures if you can show coverage, detection, alerting, and triage records. ¹

What’s the minimum evidence an auditor will accept for SI-4?

Expect to provide a monitoring scope statement, a log/telemetry coverage map, samples of alerts, and linked triage records (tickets/cases) with dispositions. Add proof that logging failures are detected and handled. ¹

How do we handle SI-4 if we outsource monitoring to an MSSP?

Treat the MSSP as a service provider and document the shared responsibility: what they monitor, what you monitor, how alerts become your tickets, and how you retain case records. Your organization still needs to produce evidence on demand. ¹

How should we document detections without exposing sensitive rule logic?

Keep a detection catalog that maps event classes to detection names, sources, and routing, and store sensitive logic in the SIEM/EDR admin system with restricted access. For audits, show the mapping, alert samples, and tickets rather than raw signatures. ¹

What are the most common monitoring blind spots in cloud environments?

Teams often collect workload logs but miss control plane logs, identity events, and “logging disabled” events. Put cloud audit logging and IdP logs in your coverage map and add alerts for logging/collector failures. ¹

How do we keep SI-4 from turning into a quarterly scramble?

Set a recurring evidence cadence (coverage review, ingestion health checks, alert aging review, tuning log updates) and store artifacts centrally. Tools like Daydream help by tying SI-4 to an owner, procedure, and evidence checklist so collection is routine. ²

Footnotes

1. NIST SP 800-53 Rev. 5

2. NIST SP 800-53 Rev. 5 OSCAL JSON