Security requirement
Embed data or capabilities in the following systems or system components to determine if CUI has been exfiltrated or improperly removed from the organization: [Organization-defined: systems or system components] .
Discussion
Many cyber-attacks target organizational information or information that the organization holds on behalf of other entities with the intent to exfiltrate that information. In addition, insider attacks and erroneous user procedures can remove information from the system in violation of organizational policies. Tainting approaches can range from passive to active. A passive tainting approach can be as simple as adding false email names and addresses to an internal database. If the organization receives email at one of the false email addresses, it knows that the database has been compromised. Moreover, the organization knows that the email was sent by an unauthorized entity, so any packets it includes potentially contain malicious code, and the unauthorized entity may have potentially obtained a copy of the database. Another tainting approach includes embedding false data or steganographic data in files to enable the data to be found via open-source analysis. An active tainting approach can include embedding software in the data that is able to "call home," thereby alerting the organization to its capture and possibly its location and the path by which it was exfiltrated or removed. This requirement does not enhance a specific requirement in SP 800-171 but can be used to strengthen the protection of CUI associated with critical programs or high value assets.
Tailoring decisions required
Resolve these values through the governing organization’s approved tailoring and risk-management process before declaring the requirement implemented.
Protection strategies supported
These classifications are carried from the official SP 800-172 OSCAL record and help explain the enhanced requirement’s defensive purpose.
Implementation perspective
Treat Tainting as an enhanced CUI protection outcome for elevated threat conditions that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to flaw remediation, malicious-code protection, monitoring, integrity, and trustworthy handling of CUI.
- Confirm the federal agency selected this enhanced requirement for the critical program or high-value asset and identify the CUI system components, services, users, and external connections in scope.
- Resolve every organization-defined parameter through an approved governance and tailoring process.
- Map each clause of the requirement to an accountable owner, implementation mechanism, and evidence source.
- Verify that inherited and shared implementations are supported by current provider evidence and responsibility boundaries.
- Collect evidence during normal operation and review changes, exceptions, and deficiencies on a risk-based cadence.
Questions to ask
- Which critical-program or high-value-asset CUI, data flows, users, and services are protected by this enhanced requirement?
- Which portions are implemented locally, inherited, shared, or not applicable, and what evidence supports that determination?
- Do the system security plan, deployed configuration, operating process, and assessment evidence tell the same story?
- What change, incident, or threshold should trigger reassessment?
Evidence and validation
- patch and remediation records
- malware protection configuration
- monitoring alerts and response records
- integrity validation and exception reports
Common failure patterns
- patch compliance hiding unsupported assets
- alerts generated without response ownership
- exceptions that never expire
- integrity monitoring excluding critical configurations
Assessment objectives and methods
Assessment objectives (1)
data or capabilities are embedded in [Organization-defined: systems or system components] to determine if CUI has been exfiltrated or improperly removed from the organization.
Examine
- System and information integrity policy
- system and information integrity procedures
- procedures addressing software and information integrity
- system design documentation
- system configuration settings and associated documentation
- policy and procedures addressing the systems security engineering technique of deception
- system security plan
- other relevant documents or records
Interview
- Personnel responsible for detecting tainted data
- personnel with systems security engineering responsibilities
- personnel with information security responsibilities
Test
- Automated mechanisms for post-breach detection
- decoys, traps, lures, and methods for deceiving adversaries
- detection and notification mechanisms
Source NIST SP 800-53 controls
These controls are referenced by the official SP 800-172 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.
Authoritative sources
- NIST SP 800-172 Revision 3 official publication ↗
- NIST SP 800-172A Revision 3 official publication ↗
- NIST OSCAL Content release used for this import ↗
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. The official publications, the responsible federal agency, and the governing contract or agreement determine applicability, tailoring, assessment depth, and required implementation.