Monitoring activities

Organization must describe the baseline of normal behaviour for the use of network and data systems, which is used as a starting point for identifying anomalies.

When defining the baseline, the following must be taken into account:

• monitoring the use of data systems during both normal and peak times
• usual times of use, places of use and frequency of use for each user and user group

Monitoring systems must be configured against the baseline to identify anomalous behavior such as:

• unplanned termination of systems or processes
• traffic related to malware or malicious IP addresses or domains
• known attack characteristics (e.g. denial of service or buffer overflow)
• unusual system use (e.g. keystroke logging)
• bottlenecks and overloads (e.g. network queues, latency levels)
• unauthorized access (actual or attempted) to systems or data
• unauthorized scanning of data systems and networks
• successful and failed attempts to access protected resources (e.g. DNS servers, web portals and file systems)
• unusual user and system behavior

Anomalies must be reported to the relevant parties in order to develop the following activities:

• auditing
• security assessment
• identification and monitoring of technical vulnerabilities

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.