Decide which parts of the ICT system to monitor

Examples of traffic filtering and monitoring systems are firewalls, routers, intrusion detection or prevention systems (IDS / IPS) and network devices / servers / applications with similar functionalities.

To ensure the functionality of filtering and monitoring:

• An owner has been appointed for the systems, who takes care of the proper operation of the system throughout the life cycle of the data processing environment
• It is the responsibility of the system owner to add, change, and delete settings for systems that filter or control traffic
• Documentation of the network and associated filtering and control systems is maintained throughout its lifecycle as an integral part of the change and settings management process
• The settings and desired operation of the systems are checked periodically during the operation and maintenance of the data processing environment and in the event of exceptional situations

Security systems (e.g. firewall, malware protection) often have the ability to record a log of events. At regular intervals, make sure that a comprehensive log is accumulated and try to identify suspicious activity. The log is also useful in investigating disturbances or violations.

An appropriate log is generated from the use of the network to enable the detection of actions relevant to cyber security.

The normal state of network traffic (traffic volumes, protocols, and connections) is known. In order to detect anomalies, there is a procedure for detecting events that are different from the normal state of network traffic (for example, anomalous connections or their attempts).

The organization must decide which parts of the ICT system it needs to monitor. These could include, for example:

• The most critical parts of the system or the parts which contain the most confidential information
• Operating systems on devices
• Internal gateways where data flows through
• Gateways between internal and external systems, e.g. to the internet
• Security products (e.g., AVS, IDS, IPS, FW etc.) in the information systems
• Systems for backup and restore

Ideally, organizations security-related monitoring should cover as much of the ICT system as possible. That makes it easier to identify unauthorized actions, security breaches and security threats as early as possible.

Organization's data systems and network must be monitored to detect abnormal use. When anomalities are detected, the organization must take the necessary measures to assess the possibility of security incident.

The monitoring should utilize tools that enable real-time or regular monitoring, taking into account the organization's requirements. Monitoring practices should be able to manage large amounts of data, adapt to changing threat environment, and send alerts immediately when necessary.

Inclusion of the following sources in the monitoring system should be considered:

• outbound and inbound network and data system traffic

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• access to critical data systems, servers, network devices and the monitoring system itself
• critical system and network configuration files
• logs from security tools (e.g. antivirus, IDS, IPS, network filters, firewalls)

Organization must also establish procedures for identifying and correcting "false positive" results, including tuning monitoring software for more accurate anomaly detection.