SI-4: Information System Monitoring
Control Family:
CSF v1.1 References:
Threats Addressed:
Next Version:
- NIST Special Publication 800-53 Revision 5:
- SI-4: System Monitoring
Control Statement
The organization:
- Monitors the information system to detect:
- Attacks and indicators of potential attacks in accordance with [Assignment: organization-defined monitoring objectives]; and
- Unauthorized local, network, and remote connections;
- Identifies unauthorized use of the information system through [Assignment: organization-defined techniques and methods];
- Deploys monitoring devices:
- Strategically within the information system to collect organization-determined essential information; and
- At ad hoc locations within the system to track specific types of transactions of interest to the organization;
- Protects information obtained from intrusion-monitoring tools from unauthorized access, modification, and deletion;
- Heightens the level of information system monitoring activity whenever there is an indication of increased risk to organizational operations and assets, individuals, other organizations, or the Nation based on law enforcement information, intelligence information, or other credible sources of information;
- Obtains legal opinion with regard to information system monitoring activities in accordance with applicable federal laws, Executive Orders, directives, policies, or regulations; and
- Provides [Assignment: organization-defined information system monitoring information] to [Assignment: organization-defined personnel or roles] [Selection (one or more): as needed; [Assignment: organization-defined frequency]].
Supplemental Guidance
Information system monitoring includes external and internal monitoring. External monitoring includes the observation of events occurring at the information system boundary (i.e., part of perimeter defense and boundary protection). Internal monitoring includes the observation of events occurring within the information system. Organizations can monitor information systems, for example, by observing audit activities in real time or by observing other system aspects such as access patterns, characteristics of access, and other actions. The monitoring objectives may guide determination of the events. Information system monitoring capability is achieved through a variety of tools and techniques (e.g., intrusion detection systems, intrusion prevention systems, malicious code protection software, scanning tools, audit record monitoring software, network monitoring software). Strategic locations for monitoring devices include, for example, selected perimeter locations and near server farms supporting critical applications, with such devices typically being employed at the managed interfaces associated with controls SC-7 and AC-17. Einstein network monitoring devices from the Department of Homeland Security can also be included as monitoring devices. The granularity of monitoring information collected is based on organizational monitoring objectives and the capability of information systems to support such objectives. Specific types of transactions of interest include, for example, Hyper Text Transfer Protocol (HTTP) traffic that bypasses HTTP proxies. Information system monitoring is an integral part of organizational continuous monitoring and incident response programs. Output from system monitoring serves as input to continuous monitoring and incident response programs. A network connection is any connection with a device that communicates through a network (e.g., local area network, Internet). A remote connection is any connection with a device communicating through an external network (e.g., the Internet). Local, network, and remote connections can be either wired or wireless.
Control Enhancements
SI-4(1): System-Wide Intrusion Detection System
Baseline(s):
The organization connects and configures individual intrusion detection tools into an information system-wide intrusion detection system.
SI-4(2): Automated Tools For Real-Time Analysis
Baseline(s):
- Moderate
- High
The organization employs automated tools to support near real-time analysis of events.
SI-4(3): Automated Tool Integration
Baseline(s):
The organization employs automated tools to integrate intrusion detection tools into access control and flow control mechanisms for rapid response to attacks by enabling reconfiguration of these mechanisms in support of attack isolation and elimination.
SI-4(4): Inbound And Outbound Communications Traffic
Baseline(s):
- Moderate
- High
The information system monitors inbound and outbound communications traffic [Assignment: organization-defined frequency] for unusual or unauthorized activities or conditions.
SI-4(5): System-Generated Alerts
Baseline(s):
- Moderate
- High
The information system alerts [Assignment: organization-defined personnel or roles] when the following indications of compromise or potential compromise occur: [Assignment: organization-defined compromise indicators].
SI-4(7): Automated Response To Suspicious Events
Baseline(s):
The information system notifies [Assignment: organization-defined incident response personnel (identified by name and/or by role)] of detected suspicious events and takes [Assignment: organization-defined least-disruptive actions to terminate suspicious events].
SI-4(9): Testing Of Monitoring Tools
Baseline(s):
The organization tests intrusion-monitoring tools [Assignment: organization-defined frequency].
SI-4(10): Visibility Of Encrypted Communications
Baseline(s):
The organization makes provisions so that [Assignment: organization-defined encrypted communications traffic] is visible to [Assignment: organization-defined information system monitoring tools].
SI-4(11): Analyze Communications Traffic Anomalies
Baseline(s):
The organization analyzes outbound communications traffic at the external boundary of the information system and selected [Assignment: organization-defined interior points within the system (e.g., subnetworks, subsystems)] to discover anomalies.
SI-4(12): Automated Alerts
Baseline(s):
The organization employs automated mechanisms to alert security personnel of the following inappropriate or unusual activities with security implications: [Assignment: organization-defined activities that trigger alerts].
SI-4(13): Analyze Traffic / Event Patterns
Baseline(s):
The organization: Analyzes communications traffic/event patterns for the information system; Develops profiles representing common traffic patterns and/or events; and Uses the traffic/event profiles in tuning system-monitoring devices to reduce the number of false positives and the number of false negatives.
SI-4(14): Wireless Intrusion Detection
Baseline(s):
The organization employs a wireless intrusion detection system to identify rogue wireless devices and to detect attack attempts and potential compromises/breaches to the information system.
SI-4(15): Wireless To Wireline Communications
Baseline(s):
The organization employs an intrusion detection system to monitor wireless communications traffic as the traffic passes from wireless to wireline networks.
SI-4(16): Correlate Monitoring Information
Baseline(s):
The organization correlates information from monitoring tools employed throughout the information system.
SI-4(17): Integrated Situational Awareness
Baseline(s):
The organization correlates information from monitoring physical, cyber, and supply chain activities to achieve integrated, organization-wide situational awareness.
SI-4(18): Analyze Traffic / Covert Exfiltration
Baseline(s):
The organization analyzes outbound communications traffic at the external boundary of the information system (i.e., system perimeter) and at [Assignment: organization-defined interior points within the system (e.g., subsystems, subnetworks)] to detect covert exfiltration of information.
SI-4(19): Individuals Posing Greater Risk
Baseline(s):
The organization implements [Assignment: organization-defined additional monitoring] of individuals who have been identified by [Assignment: organization-defined sources] as posing an increased level of risk.
SI-4(20): Privileged Users
Baseline(s):
The organization implements [Assignment: organization-defined additional monitoring] of privileged users.
SI-4(21): Probationary Periods
Baseline(s):
The organization implements [Assignment: organization-defined additional monitoring] of individuals during [Assignment: organization-defined probationary period].
SI-4(22): Unauthorized Network Services
Baseline(s):
The information system detects network services that have not been authorized or approved by [Assignment: organization-defined authorization or approval processes] and [Selection (one or more): audits; alerts [Assignment: organization-defined personnel or roles]].
SI-4(23): Host-Based Devices
Baseline(s):
The organization implements [Assignment: organization-defined host-based monitoring mechanisms] at [Assignment: organization-defined information system components].
SI-4(24): Indicators Of Compromise
Baseline(s):
The information system discovers, collects, distributes, and uses indicators of compromise.