CMMC Level 2 Practice 3.3.5: Correlate audit record review, analysis, and reporting processes for investigation and response

To meet cmmc level 2 practice 3.3.5: correlate audit record review, analysis, and reporting processes for investigation and response requirement, you must connect audit log review and alerting to your incident investigation workflow so events can be traced across systems, escalated, and acted on with documented outcomes. Assessors will look for repeatable correlation methods, defined triggers, and evidence that investigations consistently start from audit data.

Key takeaways:

• Correlation means linking related audit events across users, hosts, apps, and time to support investigations and response.
• You need documented procedures plus proof the process runs (tickets, reports, SIEM queries, case notes).
• The fastest path is to standardize log sources, centralize into a SIEM/log platform, and tie alerts directly to incident handling.

CMMC Level 2 Practice 3.3.5 is an operational requirement disguised as a logging requirement. Logging is necessary, but not sufficient. The practice expects you to review, analyze, and report audit records in a way that supports investigations and response, which implies you can reconstruct what happened, how it happened, and what you did about it across multiple systems.

For a Compliance Officer, CCO, or GRC lead, the practical challenge is making this assessable. “We have logs” will not pass if you cannot show correlation rules, review routines, escalation criteria, and completed investigations that started from audit data. You need a small set of standard scenarios (failed logins, privileged access changes, suspicious remote access, malware detections, data access anomalies) where you can prove: (1) the events were logged, (2) someone reviewed or the system alerted, (3) events were correlated into a single narrative, and (4) the result was investigated and responded to.

This page gives you requirement-level implementation guidance, with artifacts to retain and a tight execution plan aligned to CMMC Level 2 and NIST SP 800-171 Rev. 2 expectations. ¹

Requirement: CMMC Level 2 Practice 3.3.5 (mapped to NIST SP 800-171 Rev. 2 3.3.5)

Objective: Ensure audit record review, analysis, and reporting are correlated so investigations and response are timely, consistent, and based on evidence. ²

Plain-English interpretation

You must be able to take signals from audit logs (and related security telemetry), connect them into a coherent chain of activity, and use that chain to drive triage, investigation, and response actions. Correlation is what turns “a lot of logs” into “an explanation of what happened.”

Correlation can be manual (an analyst connects events across systems) or automated (SIEM correlation rules), but it must be repeatable and tied to reporting and response. The “reporting” piece means you produce outputs that lead to action: alerts, tickets, investigation notes, and management reporting where appropriate. ²

Who it applies to

Entities

• Defense contractors and subcontractors seeking CMMC Level 2 certification.
• Any organization handling DoD Controlled Unclassified Information (CUI) in scope for assessment. ³

Operational context (what’s in scope)

Applies to the CUI environment and supporting systems: identity services, endpoints, servers, network devices, cloud services, and business applications that authenticate users or access/store/transmit CUI. If an environment can affect confidentiality of CUI, its audit trails are relevant to correlation and investigation. ⁴

Regulatory text

The CMMC Level 2 practice is mapped to NIST SP 800-171 Rev. 2 requirement 3.3.5: “Correlate audit record review, analysis, and reporting processes for investigation and response.” ⁵

What the operator must do: implement a defined mechanism (people, process, and tooling) that (1) reviews and analyzes audit records, (2) correlates related events across sources, and (3) produces reports/alerts that feed investigation and incident response actions. Keep evidence that this happens in normal operations, not only during an assessment.

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

1) Define “audit correlation use cases” you will support

Pick a manageable set of investigation starters tied to your environment. Examples:

• Authentication anomalies (multiple failures then a success, impossible travel, unusual MFA prompts)
• Privileged activity (admin group changes, new service accounts, privilege escalation)
• Access to CUI repositories (bulk access, unusual downloads, access outside normal hours)
• Endpoint security detections with user/session context
  Write each use case as: signal → correlation logic → escalation trigger → investigation steps → response actions → closure criteria.

Deliverable: a short “Audit Correlation Use Case Register” owned by security operations and approved by GRC.

2) Standardize log sources and normalize identities

Correlation breaks when identities don’t line up. Do the basics:

• Ensure key systems log in a way that includes user, host, timestamp, action, result.
• Decide your identity keys (UPN/email, employee ID, device name) and map inconsistencies.
• Document time synchronization expectations (so timelines are credible during investigations).

Deliverables: logging architecture diagram, log source inventory, and field mapping notes.

3) Centralize audit data into a correlation-capable platform

A SIEM is the common approach, but the requirement is capability-based:

• Ingest logs from identity provider, endpoints, servers, firewalls/VPN, email/security tooling, and CUI repositories.
• Ensure retention supports investigation needs and that search is practical for analysts.

Deliverables: SIEM/log platform data source list, onboarding status, and sample searches.

4) Implement correlation rules (or playbook-driven manual correlation)

Create a small set of correlation rules aligned to your use cases:

• “Multiple failed logins followed by success from same IP”
• “Privileged group membership changed + login from new device”
• “Malware alert + new outbound connection + new persistence mechanism (where telemetry exists)”

If you cannot automate, define manual correlation steps that analysts follow (queries to run, how to pivot between systems, how to document linkages).

Deliverables: correlation rule list, rule logic documentation, and tuning notes.

5) Connect correlation outputs to investigations and response

This is the hinge for 3.3.5. Every high-confidence correlation should create:

• A ticket/case in your ITSM/SOAR/case management tool
• An incident severity classification method
• Assigned owner and required response times (your internal targets; document them)
• Required investigation artifacts (timeline, impacted accounts/devices, containment actions)

Deliverables: incident workflow procedure, routing rules, case templates, and evidence of closed cases.

6) Establish routine review and reporting

You need both:

• Operational review: daily/regular monitoring of alerts and notable events.
• Governance reporting: periodic summary to management (trend, major incidents, control gaps).

Keep it lightweight but consistent. Assessors expect proof that review occurs and leads to action. ²

Deliverables: meeting notes, weekly/monthly report templates, alert review checklists.

7) Test the process with realistic scenarios

Run tabletop exercises or controlled tests:

• Create a test account with known failed logins and verify correlation and ticket creation.
• Simulate privileged change and ensure it is detected and investigated.

Deliverables: test plans, results, and remediation actions.

Required evidence and artifacts to retain (assessment-ready)

Keep artifacts that prove design and operation:

Control design evidence

• Audit/logging policy and procedures covering review, analysis, correlation, and reporting ²
• Log source inventory (systems, owners, log types, criticality)
• Correlation use case register and rule documentation
• Incident response procedure showing how audit correlation feeds investigations ²
• Roles and responsibilities (SOC, IT, GRC, system owners)

Operating evidence (most important)

• SIEM dashboards/screenshots showing correlated alerts (sanitize as needed)
• Sample correlation queries and saved searches
• Case/ticket records showing: alert → triage → investigation → response → closure
• Investigation timelines referencing multiple log sources
• Alert tuning/change records (proof you maintain signal quality)
• Periodic reporting outputs and distribution list

Practical tip: maintain an “assessment evidence binder” that contains 3–5 complete investigation packages from different months (sanitized), each demonstrating cross-system correlation.

Common exam/audit questions and hangups

What an assessor asks	What they’re testing	What to show
“How do you correlate events across systems?”	Existence of a defined method	Correlation rules list + demo in SIEM or documented manual steps
“Show an investigation that started from audit logs.”	Operational use, not shelfware	Closed ticket with timeline and linked log evidence
“Who reviews alerts and how often?”	Accountability and routine operation	On-call schedule, alert queue workflow, review checklist, case ownership
“How do you ensure logs support investigations?”	Completeness and consistency	Log source inventory, required fields, time sync notes
“What happens after correlation identifies suspicious activity?”	Reporting tied to response	Incident workflow, escalation matrix, containment actions in tickets

Frequent implementation mistakes (and how to avoid them)

1. Collecting logs without correlation logic.
   Fix: document 5–10 high-value correlation use cases and implement them before expanding scope.

2. Correlation that doesn’t create an investigation record.
   Fix: require every high/critical correlated alert to open a case/ticket, even if quickly closed as benign, and capture rationale.

3. No identity normalization.
   Fix: standardize on identity keys and document mapping (usernames, device names, cloud identities).

4. Alert fatigue from noisy rules.
   Fix: implement tuning governance. Track false positives and update rule thresholds and exclusions with change records.

5. Evidence gaps.
   Fix: schedule recurring evidence capture: export weekly alert summaries and retain a small set of end-to-end investigation packages.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this specific practice. Operationally, weak correlation increases dwell time and reduces your ability to prove what happened during an incident, which raises contractual and mission risk in DoD environments. Under the CMMC program rules and assessment model expectations, inability to demonstrate operational performance can jeopardize certification outcomes. ³

Practical 30/60/90-day execution plan

First 30 days (stabilize the minimum viable process)

• Appoint owners: SOC/IT operations for monitoring, IR lead for response, GRC for evidence.
• Create the correlation use case register and pick initial scenarios.
• Inventory log sources in the CUI boundary; confirm time sync and minimum fields.
• Define the investigation ticket template and escalation matrix.

By 60 days (make it operational and provable)

• Onboard priority log sources into a central platform and validate parsing/fields.
• Build initial correlation rules and dashboards mapped to use cases.
• Connect alerts to ticket creation and document triage steps.
• Produce at least one management report based on correlated events and investigations.

By 90 days (harden, tune, and rehearse)

• Run controlled tests/tabletops for top scenarios and capture results.
• Tune correlation rules with documented changes.
• Build an evidence pack of multiple closed cases showing cross-system correlation.
• Review procedures for gaps, then lock versions for assessment readiness.

Tooling note (where Daydream fits)

If your blockers are evidence collection and repeatability, Daydream can help you map CMMC Level 2 Practice 3.3.5 to specific control activities and set up recurring evidence capture so your correlation process stays assessable without last-minute scraping. Keep the scope tight: use Daydream to track the use case register, rule list, and investigation evidence packages as living compliance artifacts. ⁶

Frequently Asked Questions

Do we need a SIEM to satisfy CMMC Level 2 Practice 3.3.5?

You need correlation capability and evidence that it drives investigations and response. A SIEM is a common way to implement it, but a documented manual correlation process can work if it is consistent, timely, and produces investigation records. ²

What’s the difference between “reviewing logs” and “correlating” them?

Reviewing can mean checking a single system’s events. Correlating means linking related events across multiple sources (identity, endpoint, network, application) into one investigative story with an outcome documented in a case or report. ²

What evidence is most convincing to an assessor?

Closed investigations that show correlated events from multiple systems, with timestamps, analyst notes, actions taken, and closure rationale. Pair that with your correlation rule documentation and routine review records. ²

How many correlation use cases should we start with?

Start with a small set that matches your real threat surface: identity anomalies, privileged access changes, remote access anomalies, endpoint detections, and CUI repository access patterns. Expand after you can show consistent investigations and tuning history.

How do we handle third-party managed security monitoring (MSSP)?

You still need accountability and evidence. Require the third party to provide correlated alert reports, investigation case notes, and access to underlying log evidence or searchable outputs, and document how escalations flow into your incident response process. ²

Can we meet 3.3.5 if some systems can’t send logs?

Gaps are manageable if you document compensating controls and show that your core CUI-supporting systems produce enough audit evidence for investigations. Track exceptions, prioritize remediation, and show how investigations proceed despite known blind spots. ⁴

Footnotes

1. NIST SP 800-171 Rev. 2; DoD CMMC Program Guidance; 32 CFR Part 170

2. NIST SP 800-171 Rev. 2

3. 32 CFR Part 170; DoD CMMC Program Guidance

4. DoD CMMC Program Guidance

5. NIST SP 800-171 Rev. 2; DoD CMMC Program Guidance

6. DoD CMMC Program Guidance; NIST SP 800-171 Rev. 2