In an incident response, what is the critical step to preserve digital evidence after identifying a suspicious file?

Maintaining chain of custody is essential in incident response because it ensures that digital evidence is preserved in a manner that is legally defensible and reliable for future analysis or potential prosecution. This process involves documenting every instance of access or handling of the evidence, detailing who collected it, when it was collected, and how it has been preserved and stored.

This meticulous record-keeping is crucial not only for maintaining the integrity of the evidence but also for validating its authenticity and credibility during subsequent investigations or court proceedings. If the chain of custody is broken, the value of the evidence may be significantly diminished, potentially affecting the outcome of any legal actions taken as a result of the incident.

In contrast, shutting down the system, logging off the user account, or simply copying evidence to a USB drive do not adequately address the critical need for evidentiary integrity and documentation. While these actions might be part of a broader response strategy, they do not ensure the proper handling and preservation of evidence as effectively as maintaining the chain of custody does.