How digital forensics works
Investigators first secure the scene and preserve volatile evidence such as memory and active network connections. They then create forensic images of storage, using write blockers and hashing to prove the copies match the originals, and record a chain of custody for each item.
Analysis examines logs, file system artifacts, registry entries, browser history, and network captures to build a timeline. Preserving integrity is crucial: changing evidence carelessly can destroy information or make it inadmissible. Findings are documented in a report that non-technical readers can follow.
Why it matters for Canadian organizations
After a suspected breach, organizations must determine what personal information was accessed. PIPEDA and Law 25 require assessing risk of harm and keeping records, and a sound forensic investigation provides the facts needed for those decisions.
Forensic evidence also supports insurance claims, law enforcement referrals, employment matters, and litigation. Engaging counsel early can help protect privilege over the investigation. Without proper preservation, organizations often cannot prove the scope of an incident, leading to over-notification or unresolved questions. Early engagement of experts preserves evidence that is easily lost.
How to implement it
Prepare before an incident: enable detailed logging, retain logs long enough, synchronize clocks, and document who to call. Have an incident response plan that includes steps for evidence preservation before systems are wiped or rebuilt.
Train responders not to reboot or tamper with compromised machines unnecessarily. Arrange access to qualified forensic specialists in advance, ideally under a retainer. Run exercises that include evidence handling so the team is practised when a real event occurs. Keep contact details for specialists where responders can find them quickly.
Frequently asked questions
What is the difference between digital forensics and incident response?
Incident response focuses on containing and recovering from an incident, while digital forensics investigates what happened and preserves evidence. The two work together, and forensic findings often guide eradication and reporting. Many incidents involve both, with forensics informing the final report.
What tools are used in digital forensics?
Examples include disk imaging tools, memory analysis frameworks, log and timeline analysis software, and network capture tools. Choice depends on the systems involved and the questions being answered. Specialists often combine commercial and open-source tools for different evidence types.
Why is chain of custody important?
Chain of custody records who handled evidence, when, and what they did. It demonstrates that evidence was not altered, which matters if findings are used in court, insurance claims, or regulatory proceedings. Without it, even accurate findings can be challenged or dismissed.
Related service: Incident response and forensics