ISMS policies
ISO/IEC 27035

Search this site

ISMS templates

< Previous standard      ^ Up a level ^      Next standard >


ISO/IEC 27035:2016+ — Information technology — Security techniques — Information security incident management (parts 1 & 2 published)


Information security controls are imperfect in various ways: controls can be overwhelmed or undermined (e.g. by competent hackers, fraudsters or malware), fail in service (e.g. authentication failures), work partially or poorly (e.g. slow anomaly detection), or be more or less completely missing (e.g. not [yet] fully implemented, not [yet] fully operational, or never even conceived due to failures upstream in risk identification and analysis). Consequently, information security incidents are bound to occur to some extent, even in organizations that take their information security extremely seriously.

Managing incidents effectively involves detective and corrective controls designed to recognize and respond to events and incidents, minimize adverse impacts, gather forensic evidence (where applicable) and in due course ‘learn the lessons’ in terms of prompting improvements to the ISMS, typically by improving the preventive controls or other risk treatments.

Information security incidents commonly involve the exploitation of previously unrecognised and/or uncontrolled vulnerabilities, hence vulnerability management (e.g. applying relevant security patches to IT systems and addressing various control weaknesses in operational and management procedures) is part preventive and part corrective action.

Scope and purpose

The standard covers the processes for managing information security events, incidents and vulnerabilities.

The standard expands on the information security incident management section of ISO/IEC 27002. It cross-references that section and explain its relationship to the ISO27k eForensics standards.

Structure and content

The standard lays out a process with 5 key stages:

  1. Prepare to deal with incidents e.g. prepare an incident management policy, and establish a competent team to deal with incidents;
  2. Identify and report information security incidents;
  3. Assess incidents and make decisions about how they are to be addressed e.g. patch things up and get back to business quickly, or collect forensic evidence even if it delays resolving the issues;
  4. Respond to incidents i.e. contain them, investigate them and resolve them;
  5. Learn the lessons - more than simply identifying the things that might have been done better, this stage involves actually making changes that improve the processes.

The standard provides template reporting forms for information security events, incidents and vulnerabilities.

Note: some terms are defined differently in the 27035 standards from those in ISO/IEC 27000, so be sure to check the applicable definitions carefully if you use this standard.

Status of the standard

ISO/IEC 27035 replaced ISO TR 18044. It was initially published in 2011 as a single standard then revised and split into three parts, later adding a fourth:


ISO/IEC 27035-1:2016 Information security incident management - Part 1: Principles of incident management

Scope & purpose: part 1 outlines the concepts and principles underpinning information security incident management and introduces the remaining part/s of the standard. It describes an information security incident management process consisting of five phases, and says how to improve incident management.

Content: the incident management process is described in five phases closely corresponding to the five phases in ISO/IEC 27035:2011 ...

  1. Plan and prepare: establish an information security incident management policy, form an Incident Response Team etc.
  2. Detection and reporting: someone has to spot and report “events” that might be or turn into incidents;
  3. Assessment and decision: someone must assess the situation to determine whether it is in fact an incident;
  4. Responses: contain, eradicate, recover from and forensically analyze the incident, where appropriate;
  5. Lessons learnt: make systematic improvements to the organization’s management of information risks as a consequence of incidents experienced.

Annexes give examples of information security incidents and cross-references to the eForensics and ISO/IEC 27001 standards.

Status: part 1 was published in 2016.

Part 1 is now being revised in line with the ongoing revision of ISO/IEC 27002.  The revision is at 3rd Working Draft stage. 

Sept A new shorter title has been approved: “Information technology - Information security incident management - Part 1: Principles and process”


ISO/IEC 27035-2:2016 Information security incident management - Part 2: Guidelines to plan and prepare for incident response

Scope & purpose: this part concerns assurance that the organization is in fact ready to respond appropriately to information security incidents that may yet occur. It addresses the rhetorical question “Are we ready to respond to an incident?” and promotes learning from incidents to improve things for the future. It covers the Plan and Prepare and Lessons Learned phases of the process laid out in part 1 - the start and end.

Content: after the usual preamble sections come 8 main clauses:

  1. Establishing information security incident management policy
  2. Updating of information security and risk management policies
  3. Creating information security incident management plan
  4. Establishing an Incident Response Team [a.k.a. CERT or CSIRT etc.]
  5. Defining technical and other support
  6. Creating information security incident awareness and training
  7. Testing (or rather exercising) the information security incident management plan
  8. Lesson learnt

... plus annexes with incident categorization examples, and notes on ‘legal and regulatory aspects’ (mostly privacy in practice).


Status: part 2 was published in 2016.

Part 2 is now being revised in line with the ongoing revision of ISO/IEC 27002.  The revision is at 3rd Working Draft stage.

A new shorter title has been proposed: “Information technology - Information security incident management - Part 2: Guidelines to plan and prepare for incident response”.

Sept Learning from incidents is being formally added to the scope.


ISO/IEC 27035-3  Information security incident management - Part 3: Guidelines for ICT incident response operations (DRAFT)

Scope & purpose: this part concerns ‘security operations’, specifically the organization and processes necessary for the information security function to prepare for and respond to ICT security events and incidents - mostly active, deliberate attacks in fact.

The scope reads (in part):

    “This document provides the guidelines for ICT incident response operations. This document is not concerned with non-ICT incident response operations such as loss of paper-based documents. The guidelines are based on the “Detection and Reporting” phase, the ”Assessment and Decision€” phase and the ”Responses” phase of the ”Information security incident management phases” model presented in ISO/IEC 27035-1:2016.”

Content: section-by-section the standard steps through the core parts of the typical incident response process i.e. incident detection; notification; triage; analysis; containment, eradication and recovery; and reporting.

Status: at Final Draft International Standard stage and should be published soon (in 2020!).


ISO/IEC 27035-4 Information security incident management - Part 4: Coordination (DRAFT)

Scope & purpose: managing major incidents usually involves coordinating responses between several organizations affected and involved in various ways.

Content: TBA.

Status: the project developing part 4 was initiated in 2020 and is now at Working Draft stage.


Personal comments

Notwithstanding the title, the 27035 standards actually concern incidents affecting IT systems and networks although the underlying principles apply also to incidents affecting other forms of information such as paperwork, knowledge, intellectual property, trade secrets and personal information. Unfortunately (as far as I’m concerned), the language is almost entirely IT-related. That, to me, represents yet another opportunity squandered: ISO27k includes but goes beyond the IT world of cybersecurity. How are organizations meant to handle incidents such as fraud and piracy where any IT element is incidental?

The is another ISO27k standard that would benefit from an explicit description of the information risks being addressed through the incident management process. Since it is literally impossible to detect and respond to every incident, a proportion of the risk has to be accepted (e.g. ‘low and slow’ attacks fly under the radar, while many hacks and malware attacks involve deliberately evading or neutralising detective as well as preventive controls), while some might be shared with third parties (e.g. business partners and insurers) or avoided (e.g. by putting even more emphasis on preventive controls). Also, the response to a major incident may well involve invoking business continuity arrangements, hence this standard should integrate with ISO 22301 etc.


< Previous standard      ^ Up a level ^      Next standard >

Copyright © 2020 IsecT Ltd.