Cyber Incident Response for decision-makers

Posted by Andrew Nanson on July 4, 2023

It is not unusual for an organisation to have a cybersecurity incident. It may be discovered through internal security controls (such as Anti-Virus, or a Security Operations Centre) , or it may be that a third-party notifies the organisation of an event.

When an organisation becomes aware of an incident it creates a chain of events that benefit from good decision-making. Most Boards are advised that they need to rehearse and prepare for a cyber incident. This can help. However, the majority of incidents do not need, or benefit from, Board-level oversight.

Whilst the decision-maker of an organisation is rarely a cyber-expert: they can play a critical role in achieving an optimum outcome. The following five-points are provided as a guide to the decision-maker.

1. Appoint the right leadership for the incident.

Incident response is a specialised field within the specialised subject of cybersecurity. The majority of people that work in IT or IT security (cybersecurity) have no experience overseeing a security incident. They may have a policy or strategy background and, whilst they may know the theory of how to respond to an incident, have very little hands-on experience.

The first decision that needs to be made is regarding the incident leadership. It may be that an in-house IT or InfoSec lead is exactly the right person to take-charge. If there is uncertainty that a suitable internal person can carry the responsibility the options are to bring in:

  • a suitably experienced person to act as a mentor and guide to the in-house lead,
  • an external specialist company to support the in-house lead,
  • an external specialist company to take-over incident management.

It can be difficult for non-expert decision-makers to gauge whether an internal person is the suitable leader for the incident. Watch-out for the following warning signs that someone may be out of their depth:

  • They are trying to apportion blame before the incident is remediated.
  • They are using more jargon than usual and it’s hard to understand all the points they are making.
  • Terms like “best practice” are used to justify an activity as opposed to an explanation.

The organisation must have confidence that the right expert is leading the response activity. But scared people rarely make the best-decisions. So even if the right person is on-point: they will probably benefit from some reassurance.

2. Set the communication tempo that is needed and try to stick to it.

Whilst it is tempting to want to know everything, every step of the way, this is rarely the most productive way of dealing with the matter. Minimising the communication burden can help maintain the focus on remediating the issue rather than communicating the issue. It is helpful to explain the tempo of communication updates or triggers that necessitate an additional briefing and then encourage the incident responders to get on with the job in-hand.

3. Agree the desired outcomes at the start.

Unfocussed incident response can quickly spiral into a mess. Set realistic outcomes such as:

  • Contain the incident to as few hosts and users as possible: this helps recovery and reduces impact,
  • Minimise downtime for the organisation and users: this helps maintain business as usual,
  • Reduce the likelihood of this impacting other organisations: this helps protect reputation,
  • Identify how the attack occurred: this helps prevent future incidents,
  • Identify which files have been compromised (exfiltrated, changed, deleted): this helps comply with legal requirements of reporting and assess the longer-term business impact. This is critical.

Setting the priorities at the start helps direct the response. As more information is discovered the priorities may change. But when an incident takes on a life of its own it can be more damaging than necessary.

4. Forensic images are almost never necessary.

The main benefit of a forensic image is if there is a likelihood that there will be a court case at some point and evidence needs to be presented in such a way that it can withstand challenge.

The percentage of court-cases that result from a cybersecurity incident is very close to zero. The cost of capturing, recording and processing computers to a forensic-level is non-trivial. It will cause significant downtime, delay the determination of the impact to the organisation and potentially cost a lot of money.

If there is reasonable suspicion that the incident was triggered by an insider: then using computer forensics may be the right route to take. If this is the case consider the use of a specialist dedicated computer forensics team that are experienced at providing expert-witness.

Taking forensic images is no longer the standard approach taken for cyber incident response and it is rarely beneficial.

5. Make sure the response is less damaging than the incident

Rebuilds are often undertaken “to be safe”, even though the technical need for this is rare. This causes downtime and increases cost. If a rebuild takes place before the incident is analysed, it could result in critical evidence of attacker-activity being destroyed.

It is difficult to respond to a situation that is not understood unless an organisation is lucky. Relying on luck is rarely a good strategy.

There are cases of organisations switching off Internet connectivity, powering down server racks and shutting down critical systems. Whilst there may be a few catastrophic scenarios where this is the right thing to do: this is incredibly disruptive to an organisation and more often than not a panic-response. Make sure that the post incident assessment considers the disruption versus the risk to determine whether the response was reasonable and proportionate. Every incident is a learning opportunity.


There is no such thing as “perfect-defence”. Many organisations will deal with cybersecurity incidents at some point and the costs associated with data-breaches is reported as averaging millions of pounds. As an incident may involve PR and legal experts as well as the cyber incident specialists: costs can mount quickly. The decision-maker can play a key role in ensuring the right business outcomes are achieved.