Logging ISO 27001: Complete Implementation & Audit Guide (A.8.15)

Logging under ISO 27001 is a critical technical control that enables organizations to record, monitor, and analyze system and user activities to detect and respond to security incidents. Defined under ISO 27001:2022 Annex A.8.15 (Logging), this control requires organizations to produce, retain, and regularly review logs across systems, applications, and infrastructure.

In real-world environments, logs act as the primary source of truth for identifying unauthorized access, investigating incidents, detecting anomalies, and supporting forensic analysis. Without effective logging, organizations operate with limited visibility and reduced ability to detect breaches, investigate suspicious activity, or demonstrate control effectiveness during audits.

Platforms such as Comply Agent can strengthen this control by linking logging configurations, evidence, and audit trails into a centralized compliance view.

Basic Information 

From the provided control structure, this control is defined as follows:

• Control ID: UC-LO-074
• Category: Logging
• Subcategory: Event Logging and Monitoring

The control description emphasizes producing and maintaining logs that capture activities, exceptions, faults, and security-relevant events. The objective is to enable organizations to detect and respond to security incidents effectively by ensuring comprehensive logging, log retention, and regular review.

In practice, event logging ISO 27001 requirements apply across a wide range of environments, including servers, applications, databases, network devices, cloud services, and authentication systems.

Logs provide essential support for:

• Identifying unauthorized access attempts
• Investigating incidents and anomalies
• Supporting forensic analysis
• Monitoring system health and security events

Without effective logging, organizations may miss warning signs, respond too slowly to incidents, or struggle to prove compliance during certification and surveillance audits.

Implementation & Guidance

The implementation guidance highlights the need for a centralized logging solution capable of aggregating, monitoring, and analyzing logs across critical systems and applications. It also stresses the importance of alerts for suspicious activity, failed logins, and critical system errors, supported by a regular review process for security logs.

Key Implementation Requirements

• Centralize logs from critical systems
• Configure alerts for suspicious activities
• Define log retention policies
• Implement regular log review processes
• Integrate incident response procedures

Step-by-Step Implementation Approach

1. Deploy Centralized Logging or a SIEM Platform
   Implement a centralized logging platform or SIEM solution such as Splunk, QRadar, or Microsoft Sentinel to:
   • Collect logs from servers, applications, and network devices
   • Normalize and correlate log data
   • Provide centralized visibility across the environment
2. Define Log Sources
   Include logs from:
   • Operating systems
   • Applications
   • Databases
   • Firewalls and network devices
   • Authentication and access management systems
3. Configure Alerts
   Set alerts for:
   • Failed login attempts
   • Privilege escalation events
   • Suspicious access patterns
   • Critical system errors and exceptions
4. Establish a Log Retention Policy
   Define:
   • Retention periods based on legal, regulatory, and business requirements
   • Secure storage and protection of logs
   • Access restrictions for log data
5. Implement a Log Review Process
   Ensure logs are:
   • Reviewed daily or at appropriate intervals based on risk
   • Analyzed for anomalies and suspicious activity
   • Escalated when incident thresholds are met
6. Integrate Logging with Incident Response
   Logs should support:
   • Incident detection
   • Investigation workflows
   • Remediation and follow-up actions

Consultant Insight

Many organizations collect logs but fail to turn them into an effective control. Common gaps include lack of event correlation, inconsistent review, alert fatigue, and weak incident response integration. Effective logging is not just about data collection. It is about continuous monitoring, actionable analysis, and documented follow-through.

Using Comply Agent, organizations can align SIEM logging compliance activities with control requirements and maintain audit-ready evidence in a structured way.

Operational Details

Key Operational Characteristics

• Frequency: Daily
• Review Cycle: Daily
• Owner Role: Security Operations Center (SOC) Analyst
• Responsible Role: Security Operations Center (SOC) Analyst
• Automation Score: 85%

The operational view shows that logging is managed as a continuous security monitoring process. Logs are automatically collected, analyzed by monitoring tools, and reviewed by security personnel to detect suspicious events and trigger incident response when needed.

How the Control Operates

• Logs are automatically collected from multiple systems
• Centralized platforms analyze and correlate events in near real time
• Alerts are generated for suspicious or high-risk activities
• SOC teams investigate, validate, and escalate events where required

Responsibilities

SOC Analyst

• Monitors logs and alerts
• Investigates suspicious activity
• Escalates incidents for response

Security Team

• Maintains logging and SIEM configuration
• Ensures log integrity and coverage
• Improves alert tuning and monitoring logic

CISO

• Oversees governance, oversight, and compliance alignment

Automation Perspective

Log monitoring ISO controls are highly automatable. Log collection, alert generation, and event correlation can all be automated at scale. Human involvement remains essential for investigation, decision-making, incident validation, and response prioritization.

Compliance & Risk Management

This control is classified as a Technical control within the Security Operations domain. The control is shown with a Level 4 maturity target, while status is marked as not started and compliance status as N/A.

Risks of Poor Logging

• Undetected security incidents
• Delayed response to breaches
• Lack of reliable forensic evidence
• Weak monitoring and detection capability
• Regulatory or audit non-compliance

Compliance Impact

Failure to implement logging effectively can result in:

• ISO 27001 audit findings
• Inability to demonstrate monitoring capability
• Weak incident detection and investigation readiness

Audit Implications

Auditors will typically assess:

• Logging coverage across systems and applications
• Centralized logging or SIEM configuration
• Log retention rules and protection measures
• Log review records
• Integration with incident response processes

A control marked as not started represents a significant compliance gap, especially where logging is expected to support monitoring, incident handling, and evidence preservation.

Framework Mappings

Key Mappings

• ISO 27001: A.8.15 Logging
• SOC 2: CC7.2
• GDPR: Article 32
• DORA: Article 10
• NIST CSF: DE.CM-1, DE.AE-1, RS.AN-1

Why This Matters

Logging is a foundational security control across nearly every major framework because it supports threat detection, monitoring, forensic investigation, and incident response. A well-governed logging process can therefore support multiple frameworks at once, reducing duplicated compliance effort.

With Comply Agent, organizations can map ISO 27001 A.8.15 logging requirements across frameworks and maintain unified compliance tracking.

Evidence Library

Key Evidence Types

1. Log Review Records (Auto-collected)
   These provide records of regular log reviews conducted by security personnel and demonstrate ongoing monitoring activity.
2. Log Retention Policy
   This policy defines log retention periods, storage requirements, and handling procedures.
3. SIEM Configuration (Auto-collected)
   This includes configuration settings of the SIEM platform, alert rules, and monitoring logic.
4. System Logs (Auto-collected)
   These are raw system and application logs collected from sources such as servers, network devices, and business applications.

Why Evidence Matters

Auditors rely on evidence to confirm that:

• Logs are generated across in-scope systems
• Logs are retained according to policy
• Logs are reviewed regularly
• Logging supports incident detection and response

A structured evidence library helps maintain continuous audit readiness and makes it easier to demonstrate that logging is not only configured, but actively governed and used.

Conclusion

Logging ISO 27001 (A.8.15) is a cornerstone of security operations. It enables organizations to detect, investigate, and respond to threats through reliable event recording, monitoring, and review.

Organizations that implement this control effectively benefit from:

• Better visibility into system and user activity
• Faster and more informed incident response
• Stronger audit readiness
• Improved security posture overall

By leveraging platforms such as Comply Agent, organizations can centralize logging evidence, map control requirements, and maintain continuous compliance visibility across ISO 27001 and related frameworks.

FAQs

1. What is Logging in ISO 27001?

It is a control that requires organizations to record and monitor system and user activities so they can detect, investigate, and respond to security incidents.

2. Which ISO clause covers logging?

ISO 27001:2022 Annex A.8.15 covers logging.

3. What evidence is required for audits?

Typical evidence includes log records, SIEM configurations, retention policies, system logs, and records of log reviews.

4. What are common audit findings?

Common issues include missing logs, incomplete coverage, weak monitoring, no retention policy, and lack of evidence showing regular review.

5. How often should logs be reviewed?

This is usually daily for critical systems, though review frequency should always be based on risk, system criticality, and monitoring capability.

6. How can Comply Agent help?

Comply Agent can centralize logging evidence, map controls to requirements, support compliance tracking, and improve audit readiness.