MON-21: Unauthorized Activities
Mechanisms exist to monitor for unauthorized activities, accounts, connections, devices and software.
Renumbered: Formerly MON-16.3 in SCF 2025.4.
Control Question: Does the organization monitor for unauthorized activities, accounts, connections, devices and software?
General (6)
| Framework | Mapping Values |
|---|---|
| CIS CSC 8.1 | 2.3 |
| CIS CSC 8.1 IG1 | 2.3 |
| CIS CSC 8.1 IG2 | 2.3 |
| CIS CSC 8.1 IG3 | 2.3 |
| NIST CSF 2.0 (source) | DE.CM-03 |
| PCI DSS 4.0.1 (source) | A3.2.6.1 |
US (1)
| Framework | Mapping Values |
|---|---|
| USA Federal NERC CIP 2024 | CIP-006-6 1.4 |
EMEA (4)
| Framework | Mapping Values |
|---|---|
| EMEA UK DEFSTAN 05-138 2024 | 4106 |
| EMEA UK DEFSTAN 05-138 - L1 2024 | 4106 |
| EMEA UK DEFSTAN 05-138 - L2 2024 | 4106 |
| EMEA UK DEFSTAN 05-138 - L3 2024 | 4106 |
APAC (2)
| Framework | Mapping Values |
|---|---|
| APAC India RBI Digital Payments 2021 | 56.h |
| APAC Malaysia RMiT 2025 | A2-C4 |
Capability Maturity Model
Level 0 — Not Performed
Practices are non-existent, based on the inability to demonstrate an implemented and operational capability. A reasonable person would conclude the control is not being performed.
Level 1 — Performed Informally
SCR-CMM Level 1 criteria definitions are not available for this control: ▪ A reasonable person would conclude this control requires a structured process. ▪ At this level of maturity, the "ad hoc" nature of performing a capability informally would indicate the intent of the control is not met due to a lack of consistency and formality.
Level 2 — Planned & Tracked
Continuous Monitoring (MON) capabilities are requirements-driven, but are not standardized across the entity (e.g., local/regional level consistency). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with MON domain capabilities are formally documented and centrally-managed by the entity. ▪ Standardized Operating Procedures (SOP) associated with MON domain capabilities are documented and maintained by process owners. ▪ IT and/or cybersecurity personnel work with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with MON domain capabilities to address applicable statutory, regulatory and/or contractual requirements for Technology Assets, Applications, Services and/or Data (TAASD). ▪ Continuous monitoring-related controls are primarily administrative and preventative in nature (e.g., policies, standards and procedures & guidelines). ▪ Continuous monitoring may be a defined function (e.g., team or department) or assigned as an additional duty to existing IT and/or cybersecurity personnel.
Level 3 — Well Defined
Continuous Monitoring (MON) capabilities are standardized across the entity for applicability to People, Processes, Technologies, Data and/or Facilities (PPTDF) to ensure consistency for Technology Assets, Applications, Services and/or Data (TAASD). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with MON domain capabilities are formally documented and centrally-managed by the entity's Governance, Risk & Compliance (GRC) team, or similar function. ▪ Cybersecurity personnel use a structured process via Standardized Operating Procedures (SOP) to review and analyze logs. ▪ A Security Operations Center (SOC) team, or similar function, is appropriately staffed and supported to implement and maintain MON domain capabilities. ▪ Technology is leveraged to enhance the efficiency and accuracy of continuous monitoring operations (e.g., Security Incident Event Manager (SIEM)). ▪ The entity's Governance, Risk & Compliance (GRC) team, or similar function, works with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with MON domain capabilities to address Minimum Compliance Requirements (MCR) (e.g., applicable statutory, regulatory and/or contractual requirements) and Discretionary Security Requirements (DSR) (e.g., entity-required controls). ▪ Secure Baseline Configurations (SBC) enforce security event logging to contain sufficient information to establish necessary details of activity and allow for forensics analysis. ▪ An implemented and operational capability exists to monitor for unauthorized activities, accounts, connections, devices and software.
Level 4 — Quantitatively Controlled
Utilize SCR-CMM Level 3 criteria definitions: ▪ There are no defined Level 4 criteria, since it is reasonable to assume a quantitatively-controlled process is not necessary to operationalize this control. ▪ While it may be possible to develop “metrics-driven” capabilities for this control, the criteria would be organization-specific to define.
Level 5 — Continuously Improving
Utilize SCR-CMM Level 3 or Level 4 (if available) criteria definitions: ▪ There are no defined Level 5 criteria, since it is reasonable to assume a continuously-improving process is not necessary to operationalize this control. ▪ Level 5 capabilities should be considered “world-class” where the control builds on Level 4 capabilities, but are continuously improving through Artificial Intelligence (AI) and/or Machine Learning (ML) technologies. ▪ While it may be possible to develop responsive capabilities for this control through the use of AI and/or ML technologies, the criteria would be organization-specific to define.
Assessment Objectives
- MON-21_A01 unauthorized activities are defined.
- MON-21_A02 personnel or roles to be notified when unauthorized activities are detected are defined.
- MON-21_A03 methods to detect unauthorized activities are identified.
- MON-21_A04 monitoring mechanisms are configured to detect unauthorized activities.
- MON-21_A05 personnel or roles are notified when unauthorized activities are detected.
Evidence Requirements
- E-MON-07 Situational Awareness
-
Documented evidence of the organization leveraging knowledge of event log generation to gain situational awareness of cross-domain activities (e.g., technology issues, security events, policy violations, service provider activities, remote workforce activities, physical security events, etc.).
Event Log Monitoring
Technology Recommendations
Micro/Small
- Indicators of Compromise (IoC)
- Indicators of Exposure (IoE)
- Managed Security Services Provider (MSSP)
Small
- Indicators of Compromise (IoC)
- Indicators of Exposure (IoE)
- Security Incident Event Manager (SIEM)
- Managed Security Services Provider (MSSP)
Medium
- Indicators of Compromise (IoC)
- Indicators of Exposure (IoE)
- Security Incident Event Manager (SIEM)
- Extended Detection and Response (XDR)
- Managed Security Services Provider (MSSP)
Large
- Indicators of Compromise (IoC)
- Indicators of Exposure (IoE)
- Security Incident Event Manager (SIEM)
- Extended Detection and Response (XDR)
- Managed Security Services Provider (MSSP)
Enterprise
- Indicators of Compromise (IoC)
- Indicators of Exposure (IoE)
- Security Incident Event Manager (SIEM)
- Extended Detection and Response (XDR)
- Managed Security Services Provider (MSSP)