ISO/IEC 27001:2022·Annex A A.8.16·medium·Component: Technological controls

What this control requires

Networks, systems and applications shall be monitored for anomalous behavior and appropriate actions taken to evaluate potential information security incidents.
— ISO/IEC 27001:2022, Annex A A.8.16

In plain English

Networks, systems and applications shall be monitored for anomalous behavior and appropriate actions taken to evaluate potential information security incidents. In practice, this means you can prove you information information security-level controls on a defined cadence.

Why it matters

ISO 27001 certification depends on showing each Annex A control is either implemented or explicitly justified for exclusion in the Statement of Applicability (SoA). Certification bodies sample controls during surveillance audits, and a missing SoA entry — or implementation that doesn't match the SoA wording — is a finding.

What an auditor looks for

An ISO 27001 lead auditor looks for: (1) an SoA entry covering the control with justification, (2) a documented procedure or policy implementing it, (3) records that prove the procedure runs (logs, tickets, training records) and (4) management-review evidence that effectiveness is monitored.

Within Technological controls, the assessor will trace your implementation back to the catalogue reference (Annex A A.8.16) and look for objective evidence on the latest two assessment cycles.

How to implement

Cloud Posture

CSPM. Run Wiz / Prisma / Defender for Cloud / Security Command Center over every account; auto-ticket findings above your accepted-risk threshold.

Network Security

AWS. VPC Flow Logs to S3, default-deny security groups, AWS Network Firewall for north-south, and Transit Gateway for hub-and-spoke segmentation.

Azure. NSGs with deny-by-default, Azure Firewall Premium with TLS inspection, Private Endpoints for PaaS, and Microsoft Defender for Cloud's secure score for drift.

GCP. VPC Service Controls perimeters around sensitive APIs, Cloud NGFW Enterprise for L7 inspection, Private Service Connect for managed services.

Operational checklist

  • Information. Document the trigger, the owner and the cadence.
  • Response. Document the trigger, the owner and the cadence.
  • Security. Document the trigger, the owner and the cadence.
  • Networks. Document the trigger, the owner and the cadence.
  • Scope: information security, information security incidents, networks.

Evidence to collect

  • Infra Scan. Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings.
  • Ticketing Workflow. ticketing_workflow evidence

SIEM detections (Defender for Cloud, Splunk) and incident tickets (ServiceNow, Jira) show anomalous activity is monitored and triaged.

Common pitfalls

  • Treating CSPM findings as a backlog instead of a hot queue: findings older than the policy SLA accumulate until the auditor asks why.
  • Default-allow egress rules; East-West traffic with no segmentation; jump hosts on the public internet with password auth.

Related controls in ISO/IEC 27001:2022

References

Topics: logging monitoringincident responseevent alertcloud posturenetwork securitycontinuous monitoring