Most organizations that fail CMMC Audit and Accountability assessments are not organizations that have no logs. They are organizations with logs that do not cover the right events, that are not reviewed against defined baselines, that are stored without integrity controls, or that exist in formats that take days to compile into assessment evidence.
Logging and continuous monitoring under CMMC is not a storage problem. It is a strategy problem. The requirement is not to collect data — it is to maintain the audit infrastructure that would detect, document, and support response to a security incident involving CUI systems. That requirement has operational teeth: if your logging strategy would not have detected a credential theft in progress, it does not meet CMMC AU intent regardless of how many gigabytes of logs you retain.
Overview
CMMC AU domain requirements mandate audit event generation, protection, review, and retention across CUI systems. The continuous monitoring requirements under CA.2.157 and CA.3.161 extend that obligation to ongoing security control effectiveness assessment. Together, they require not just that logs exist, but that the logging infrastructure produces actionable security visibility — and that it is reviewed consistently enough to make that visibility operationally meaningful.
- Audit event coverage must include the event types that matter for CUI protection — authentication, privilege use, object access, system events
- Log integrity controls prevent audit records from being modified or deleted by the same actors they are designed to monitor
- Review cadences must be frequent enough to detect security events during attacker dwell time, not after damage is done
- Continuous monitoring extends the obligation from log collection to ongoing security control effectiveness verification
- Assessment evidence requires that logs are in formats that support audit review without weeks of compilation effort
The 5 Why’s
- Why do most DIB contractor logging implementations fall short of CMMC AU requirements despite collecting large log volumes? Volume is not coverage. Organizations that collect firewall logs, Windows event logs, and endpoint telemetry may still miss the authentication anomalies, privileged account actions, and object access events that CMMC AU specifically requires. Coverage assessment — verifying that the specific event types CMMC mandates are actually being captured for every CUI-touching system — is the gap most organizations discover late.
- Why does log integrity matter specifically for CMMC compliance purposes? CMMC AU.3.045 requires protection of audit information from unauthorized access, modification, and deletion. Logs stored on systems accessible to the accounts they monitor can be modified by the same actors they are intended to catch. Log forwarding to immutable storage — SIEM infrastructure, write-once log repositories — is the control that makes audit records trustworthy as evidence.
- Why is the review requirement the most operationally demanding part of CMMC AU compliance? Log collection is a configuration exercise. Log review against defined baselines is an ongoing operational practice that requires staff time, defined review procedures, and escalation paths for anomaly findings. Organizations that configure logging but do not establish regular review practices have the data and not the insight — which does not satisfy CMMC AU.2.042 (review and analysis) or support incident detection.
- Why does continuous monitoring under CMMC extend beyond the AU domain? CA.2.157 (plan of action and milestones) and CA.3.161 (monitor security controls on an ongoing basis) establish that CMMC compliance is not a point-in-time status — it is a continuous operational condition. Security controls must be assessed for effectiveness on an ongoing basis, with findings documented and remediated on defined timelines. Logging and monitoring are the infrastructure that makes that ongoing assessment possible.
- Why does assessment evidence preparation become a major cost driver when logging strategy is wrong? Assessors reviewing AU domain compliance need to see that required event types are being captured, that logs are protected, and that review is occurring. Organizations with fragmented logging across multiple systems in inconsistent formats spend weeks compiling evidence packages. Organizations with centralized, structured logging in assessment-ready formats produce that evidence in hours. The logging strategy determines the assessment cost as much as the compliance status.
CMMC Logging Strategy: What to Capture
Required Audit Event Types
CMMC AU requirements, read against NIST 800-171 AU controls, require logging of:
- Authentication events — successful and failed login attempts across all CUI-touching systems; MFA authentication events; account lockout events
- Privileged account actions — use of administrative accounts; privilege escalation events; privileged commands executed
- Object access events — access to CUI files, databases, and storage; access denied events; file transfer and copy operations
- Account management events — account creation, modification, deletion, and permission changes; group membership changes
- System events — system startup and shutdown; security policy changes; audit log clearing attempts
- Network events — connection attempts to and from CUI systems; VPN and remote access session establishment and termination
Coverage Assessment Process
For each CUI-touching system, verify:
- Which of the required event types are generated by the system natively
- Which require additional configuration to capture
- Which cannot be captured at the system level and require network-level capture
- That log forwarding from each system to centralized storage is operational and monitored for gaps
CMMC Continuous Monitoring Strategy
Security Control Effectiveness Monitoring
Continuous monitoring under CMMC CA domain requirements is not just log review. It is ongoing verification that security controls are working as designed:
- Access control effectiveness — periodic verification that access control configurations match defined policies; detection of drift between documented policy and enforced access
- Configuration baseline adherence — continuous monitoring of system configurations against approved baselines; alerting on configuration changes that deviate from baseline
- Vulnerability posture — ongoing vulnerability scanning with defined remediation timelines; tracking of open vulnerabilities against POAM milestones
- Patch currency — monitoring of patch status across CUI-touching systems against defined patch management timelines
Review Cadences
- Real-time alerting — authentication anomalies, privileged account misuse, and access to high-sensitivity CUI objects trigger real-time alerts, not daily batch review
- Daily review — access denied event patterns, failed authentication aggregates, and unusual access time patterns reviewed daily
- Weekly review — configuration change logs, account management events, and vulnerability scan results reviewed weekly
- Monthly review — full audit log completeness verification; access control policy adherence review; POAM status update
Assessment Evidence Architecture
Logging infrastructure designed with assessment evidence generation in mind produces:
- Event type coverage documentation — mapping of required CMMC AU event types to the systems and logging sources that capture each
- Log integrity verification — documentation of log forwarding configurations and immutable storage architecture
- Review procedure documentation — written procedures for each review cadence, with evidence of execution (review records, anomaly findings, escalation logs)
- Retention compliance documentation — evidence that log retention meets the CMMC-required 90-day active retention with three-year archive
A Simple Logging and Monitoring Gap Assessment
Your CMMC logging and monitoring implementation has gaps if:
- Authentication events from all CUI-touching systems are not centrally collected and reviewable
- Log review is performed on an ad hoc basis rather than against defined procedures and cadences
- Logs are stored on systems accessible to the accounts they monitor without write-protection controls
- Configuration drift from approved baselines is not monitored or alerted on
- Compiling assessment evidence for AU domain review would require more than a few hours of effort
Final Takeaway
CMMC logging and continuous monitoring compliance is not a storage infrastructure investment. It is a security operations investment — the strategy, configuration, procedures, and staffing that turn log data into security visibility and compliance evidence. Organizations that invest in that strategy produce environments where security events are detected during attacker dwell time and CMMC assessments are supported with evidence that was accumulating continuously, not assembled under deadline.
Build Your CMMC Logging and Monitoring Strategy With Mindcore Technologies
Mindcore Technologies works with DIB contractors to design and implement CMMC-compliant logging and continuous monitoring strategies — event coverage assessment, centralized log architecture, review procedure development, and assessment evidence infrastructure that produces operational security visibility and assessment-ready compliance documentation.
Talk to Mindcore Technologies About CMMC Logging and Monitoring →
Contact our team to assess your current logging coverage against CMMC AU requirements and build the monitoring strategy that closes the gaps.
