What Are the Biggest Mistakes Organizations Make When Responding to a Breach?

After responding to hundreds of security incidents across industries ranging from financial services to manufacturing to healthcare, MSInfo Services' incident response team has observed consistent patterns in the mistakes that organizations make during a breach — mistakes that turn manageable security events into organizational crises.

The single most common mistake is acting before understanding. The pressure to 'do something' — shut down systems, reset passwords, engage vendors — is intense in the early hours of an incident. But taking actions before understanding the scope of the compromise often makes the situation worse. Reimaging a compromised system before capturing a forensic image destroys the evidence needed to understand how the attacker got in and where else they may have been. Resetting passwords before identifying all compromised accounts tips off the attacker, who then escalates from their remaining access before being cut off.

The second major mistake is inadequate scoping. Organizations often identify one compromised system and treat it as the full extent of the incident — without asking how the attacker got to that system and where they went from there. In most sophisticated attacks, the system that triggers the initial alert is not the first one compromised — it's one of many. Thorough investigation requires examining authentication logs, network flows, and endpoint telemetry across the entire environment, not just the identified affected systems.