How does SENTRY protect CUI against nation-state threat actors?

Nation-state actors targeting DIB contractors operate slowly and persistently — establishing access, moving laterally over weeks or months, and staging CUI before exfiltration. SENTRY addresses this through proactive threat hunting calibrated against known APT TTPs, continuous CUI access pattern monitoring, anomaly detection for low-and-slow unauthorized access, and threat intelligence enrichment from sources focused on DIB-targeted adversaries. Reactive detection alone is insufficient against these actors; the combination of continuous monitoring and proactive hunting is required.

SOC for Defense Contractors: Continuous Monitoring for CMMC & NIST 800-171

CMMC 2.0 Level 2 requires compliance with NIST SP 800-171 — including the Audit and Accountability and Incident Response control families that mandate continuous monitoring, documented alert review, and a tested incident response capability. Armorstack SENTRY delivers managed SOC services designed to satisfy these requirements, protect Controlled Unclassified Information, and produce the documentation that C3PAO assessors expect to see.

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The Direct Answer: How a Managed SOC Satisfies CMMC Continuous Monitoring Requirements

CMMC 2.0 Level 2 maps directly to the 110 security requirements of NIST SP 800-171 Rev. 2. Among these requirements, the Audit and Accountability (AU) domain and the Incident Response (IR) domain contain the controls most directly addressed by a managed Security Operations Center. These are not aspirational controls — they are assessed by C3PAOs as part of Level 2 certification and by government contractors as part of Level 1 annual self-assessments. The absence of a documented, operational monitoring capability is among the most common finding categories in CMMC readiness assessments.

The specific controls that a managed SOC addresses are AU.3.045 (alerting on audit logging process failures), AU.3.046 (reviewing audit logs for indicators of inappropriate activity), IR.2.092 (tracking, documenting, and reporting incidents), IR.2.093 (testing the incident response capability), and IR.3.098 (the enhanced practice for testing, training, and incident response exercises required for organizations seeking CMMC Level 3 equivalence).

This page covers each of these controls in detail, explains the CUI context that makes continuous monitoring operationally critical for DIB contractors, and maps the SENTRY SOC program to the specific requirements that assessors evaluate. For the complete CMMC compliance program — spanning all 110 practices including access control, configuration management, and system protection — see Armorstack’s CMMC Readiness Program.

The DIB Threat Landscape: Nation-State Actors and the CUI Imperative

Defense Industrial Base Contractors Are Primary Targets for Advanced Persistent Threats

The Defense Industrial Base is among the most actively targeted sectors by nation-state threat actors — specifically because DIB contractors hold Controlled Unclassified Information that represents direct strategic value to adversaries seeking to understand U.S. defense programs, technology development, and acquisition strategies without the risk of directly attacking a classified system. The value of CUI to a sophisticated adversary is high enough to justify sustained, patient intrusion campaigns that may operate for months before any destructive or exfiltration action occurs. These are not opportunistic ransomware attacks driven by financial motivation — they are targeted intelligence collection operations run by adversaries with significant technical capability and unlimited patience.

The Patient Adversary Problem: Why Threat Hunting Is Required, Not Optional

Nation-state actors targeting the DIB do not operate the way that commodity ransomware groups do. They establish initial access — frequently through spearphishing, supply chain compromise, or credential theft — and then move slowly, carefully, and quietly through the target environment. They establish persistence mechanisms designed to survive standard security tool detection. They collect and stage data gradually over weeks or months, minimizing any single exfiltration event that might trigger a volume-based anomaly alert. They may have a specific collection objective and will wait, maintaining access, until that objective is within reach. Reactive detection — waiting for rules to fire — finds only the fraction of this activity that is noisy enough to trigger a rule. Proactive threat hunting — SENTRY’s hypothesis-driven campaign model — finds the activity that has not triggered rules yet by searching for behavioral indicators characteristic of these adversary TTPs.

The Subcontractor Risk: You Are Responsible for Your Supply Chain’s Access

CMMC 2.0 requirements flow down through the defense supply chain. Prime contractors are required to ensure that subcontractors handling CUI meet applicable CMMC requirements. This means that a prime contractor’s CMMC posture is only as strong as the weakest monitored access point in their supply chain. SENTRY’s third-party risk monitoring capability — tracking activity from partner and vendor connections in your environment — provides visibility into the access patterns of entities that may have legitimate access to your systems but whose own security posture is outside your direct control.

CUI Exfiltration Is the Compliance Event That Cannot Be Undone

Unlike a ransomware event, which is operationally disruptive but recoverable through backup and restoration, a CUI exfiltration event creates a permanent compliance and contractual liability. DFARS clause 252.204-7012 requires contractors to report cyber incidents to DoD within 72 hours of discovery and to preserve and protect images of all known affected information systems. The 72-hour reporting window begins at discovery — and as with HIPAA, the question of when discovery should have occurred is relevant to how DoD assesses the incident. Continuous monitoring with a documented detection and response capability directly affects both the speed of discovery and the credibility of the organization’s response when reporting to DoD.

SENTRY SOC: NIST 800-171 and CMMC 2.0 Control Mapping

The following table maps NIST SP 800-171 Rev. 2 requirements — which are the CMMC 2.0 Level 2 practices — to SENTRY SOC capabilities. Control identifiers reference the NIST 800-171 Rev. 2 structure used in CMMC 2.0 assessments. Organizations pursuing Level 3 equivalence should also note the IR.3.098 enhanced practice entry.

NIST 800-171 Control	CMMC Domain	Requirement Summary	How SENTRY SOC Addresses It
3.3.1 (AU.2.041)	Audit & Accountability	Create and retain system audit logs to enable the monitoring, analysis, investigation, and reporting of unlawful or unauthorized system activity	Managed SIEM handles audit log ingestion, storage, and retention for all in-scope systems; log retention configurations are set per CMMC and organizational requirements from engagement start
3.3.2 (AU.2.042)	Audit & Accountability	Ensure that the actions of individual system users can be traced to those users so they can be held accountable for their actions	Identity system telemetry correlation links system activity to individual user accounts; anomalous privileged activity is attributed and documented at the user level
3.3.5 (AU.3.045)	Audit & Accountability	Correlate audit record review, analysis, and reporting processes for investigation and response to indications of unlawful, unauthorized, suspicious, or unusual activity; alert in the event of an audit logging process failure	Automated alerting on log source failures; SENTRY analysts receive and respond to log collection failure alerts; correlation across log sources for cross-system indicators of compromise
3.3.6 (AU.3.046)	Audit & Accountability	Provide audit record reduction and report generation to support on-demand analysis and reporting	SIEM-based audit log review with documented analyst review cadence; on-demand audit report generation for SSP documentation and C3PAO assessment evidence; monthly executive reporting summarizing monitoring activity
3.6.1 (IR.2.092)	Incident Response	Establish an operational incident-handling capability for organizational systems that includes preparation, detection, analysis, containment, recovery, and user response activities	Full incident response lifecycle handled by SENTRY: detection and analysis by SOC analysts, containment actions executed by the response team, recovery guidance provided, user notification coordinated; all steps documented
3.6.2 (IR.2.093)	Incident Response	Track, document, and report incidents to designated officials and/or authorities both internal and external to the organization	Incident tracking in SENTRY’s case management system; structured incident reports produced for internal stakeholders; DFARS 252.204-7012 72-hour reporting support for CUI-involved incidents; documentation chain maintained from detection through closure
3.6.3 (IR.3.098)	Incident Response (Enhanced)	Test the organizational incident response capability — this enhanced practice is relevant to organizations seeking CMMC Level 3 equivalence under NIST SP 800-172	Annual tabletop exercises and quarterly detection scenario testing; documented test results and after-action reports structured for C3PAO assessment review; VERITY advisory overlay for Level 3 gap analysis and System Security Plan development
3.14.7 (SI.3.219)	System & Information Integrity	Identify unauthorized use of organizational systems	Continuous monitoring for behavioral anomalies indicating unauthorized system use; CUI access pattern monitoring with anomaly detection; threat hunting for low-and-slow unauthorized access patterns characteristic of nation-state activity

SENTRY SOC addresses the monitoring and incident response subset of the NIST 800-171 control set. A complete CMMC 2.0 Level 2 program spans all 14 domains and 110 practices. Armorstack’s VERITY advisory team manages the complete System Security Plan (SSP), Plan of Action and Milestones (POA&M), and C3PAO assessment preparation. See the full CMMC Readiness Program.

DFARS 252.204-7012: The 72-Hour Reporting Requirement and What It Demands of Your Monitoring Program

DFARS clause 252.204-7012, “Safeguarding Covered Defense Information and Cyber Incident Reporting,” requires contractors to rapidly report cyber incidents to DoD through the DIBNet portal. The reporting window is 72 hours from discovery of the incident. The clause defines a cyber incident as actions taken through the use of computer networks that result in a compromise or an actual or potentially adverse effect on an information system or the information residing therein.

What 72 Hours Requires Operationally

A 72-hour reporting window is extremely tight when measured against the operational reality of a complex cybersecurity incident. Within 72 hours of discovery, the contractor must: determine that a reportable incident has occurred; identify and preserve images of all known affected information systems; review the compromised systems and assess the scope of the incident; and submit the report through DIBNet with the required data elements. Each of these steps requires forensic capability, documentation discipline, and the operational capacity to execute them simultaneously with incident containment. An organization that discovers a breach on a Friday afternoon has approximately 72 hours — including the weekend — to complete this process.

Discovery Speed Determines Whether 72 Hours Is Sufficient

As with HIPAA’s notification clock, the 72-hour DFARS reporting window is measured from discovery. Continuous SOC monitoring directly determines how quickly discovery occurs. An organization whose security team works business hours and whose monitoring system runs unreviewed alerts overnight may not “discover” a breach that occurred on Thursday evening until Monday morning — effectively starting the 72-hour clock four days after the incident began. At that point, the 72-hour window may already be insufficient to complete the required preservation, analysis, and reporting before the deadline. Continuous monitoring collapses this dwell time, starting the discovery clock closer to the actual incident and giving the response team the full 72 hours to work with.

Malware Submission Requirement

DFARS 252.204-7012 also requires contractors to submit malware associated with a reported cyber incident to DoD’s Cyber Crime Center (DC3) upon request. SENTRY’s incident response documentation captures malware artifacts, hash values, and forensic evidence at the time of containment, ensuring that the required evidence package is available if DC3 requests it — without requiring the organization to reconstruct a forensic evidence chain after the fact.

Frequently Asked Questions: SOC for Defense Contractors

Does a managed SOC satisfy the CMMC 2.0 AU and IR domain requirements?

SENTRY SOC directly addresses the CMMC 2.0 Level 2 Audit and Accountability (AU) practices — specifically AU.2.041, AU.2.042, AU.3.045, and AU.3.046 — and the Incident Response (IR) practices — specifically IR.2.092, IR.2.093, and IR.3.098 for Level 3-equivalent organizations. These are the practices most commonly cited as gaps in CMMC readiness assessments for mid-market DIB contractors. CMMC is a 110-practice, 14-domain program; SENTRY addresses the monitoring and incident response subset. A complete CMMC Level 2 program requires SSP documentation, POA&M management, and assessment preparation across all domains — see Armorstack’s CMMC Readiness Program for the full picture.

We self-assessed at CMMC Level 1 — do we need a managed SOC?

CMMC Level 1 covers 17 basic safeguarding practices focused on Federal Contract Information (FCI), not Controlled Unclassified Information (CUI). It does not include the AU or IR control families. If your contracts involve CUI — which most DoD prime and subcontracts above a certain threshold do — you are subject to CMMC Level 2 requirements, which include the continuous monitoring practices. The determination of whether your contracts involve CUI is made based on contract language and the data you handle, not on the CMMC level you have self-reported. If you are uncertain whether your environment is subject to Level 2 requirements, that question should be resolved before the next contract renewal or new award review.

Can SENTRY help us prepare for a C3PAO assessment?

Yes. SENTRY produces the evidence documentation that C3PAO assessors review for AU and IR domain practices: audit log review records, incident response documentation, alert management logs, and incident response testing results. Armorstack’s VERITY advisory team manages SSP development and POA&M maintenance and coordinates the complete assessment preparation process across all 110 practices. The combination of SENTRY operational evidence and VERITY advisory governance produces the documentation package that supports a credible Level 2 assessment. Engagements that begin with the 90-Day Proof give organizations a concrete evidence base for the AU and IR domains within the first quarter.

How does SENTRY address the DFARS 72-hour cyber incident reporting requirement?

DFARS 252.204-7012 requires reporting to DoD within 72 hours of discovery of a cyber incident involving covered defense information or systems. SENTRY’s continuous monitoring capability reduces dwell time — the gap between incident occurrence and discovery — which gives your organization the maximum available time within the 72-hour window. SENTRY’s incident response documentation captures the data required for DIBNet reporting: incident timeline, affected systems inventory, indicators of compromise, and forensic artifact preservation. SENTRY analysts support the reporting process but the legal obligation to report remains with the contractor; Armorstack’s VERITY advisory team can engage outside legal counsel coordination for significant incidents where representation is appropriate.

What does threat hunting look like for a defense contractor environment specifically?

SENTRY threat hunting campaigns for DIB environments are calibrated against the tactics, techniques, and procedures associated with nation-state actors known to target the defense industrial base — including APT groups that use living-off-the-land techniques, supply chain compromise vectors, and long-term persistent access strategies. Hunt hypotheses are drawn from MITRE ATT&CK, NSA and CISA joint advisories on DIB-targeted threat actors, and current threat intelligence about active campaigns. For CUI-handling environments specifically, hunt campaigns focus on CUI data staging and exfiltration patterns, anomalous privileged access to systems containing CUI, and persistence mechanisms designed to survive standard detection. Hunt results are documented in the format required for IR.3.098 evidence.

Does SENTRY cover subcontractor environments in addition to the prime contractor?

SENTRY engages at the organizational level — the engagement is scoped to your environment, including your on-premises infrastructure, cloud workloads, and remote workforce. Subcontractors in your supply chain who handle CUI under your prime contract carry their own CMMC obligations; Armorstack can engage them directly on CMMC readiness and monitoring if they choose to pursue a SENTRY engagement. SENTRY does monitor third-party access into your environment — vendor connections, partner system integrations, and managed service access — as part of your organization’s monitoring scope, providing visibility into the access patterns of external entities with connections to your systems.

CMMC AU and IR Gaps Are Among the Most Common Findings. Close Them Before the Assessment.

SENTRY delivers managed SOC services that address the NIST 800-171 Audit and Accountability and Incident Response control families — the monitoring practices most frequently cited in CMMC readiness gap assessments. Documentation is structured for C3PAO review. DFARS 72-hour reporting support is included.