I was on a call the other day discussing security incident and breach response. One of the things that we both highlighted is the difference between an event, incident and breach. Confusing these three could land you in a lot of trouble.
What is an Event?
According to NIST, an event is any observable occurrence in a system or network. Events are typically routine, benign, and don’t necessarily signify a problem. They may include activities like logging in, accessing a file, or changes in system configurations. In essence, an event is a recorded action or series of actions, and it’s often logged for further monitoring, review, or analysis.
NIST defines an event as “any observable occurrence in a system or network.” These can be mundane actions like system access, file transfers, or network connections.
Example of an Event
- A user successfully logging into a system.
- A file being accessed or modified.
- A scheduled backup being completed.
Events themselves are not inherently harmful, but they are useful to track because they may serve as indicators of larger issues if patterns emerge. In short, events provide context and can serve as the foundation for identifying incidents.
What is an Incident?
In NIST’s cybersecurity framework, an incident is a “violation or imminent threat of violation of computer security policies, acceptable use policies, or standard security practices.” Incidents are more serious than events, as they typically involve unauthorized or malicious activity, or actions that jeopardize confidentiality, integrity, or availability of systems and data.
An incident may be triggered by various factors, such as cyberattacks, system failures, or human errors. Unlike events, incidents usually demand immediate attention and response, as they may lead to significant harm if not addressed.
Example of an Incident:
- A user account being hacked and used to access sensitive data.
- Malware infecting a system and compromising data integrity.
- A Denial-of-Service (DoS) attack disrupts network services.
While all incidents are events (since they are observable occurrences), not all events are incidents. Incidents represent a threat or actual damage to system security, requiring a response to mitigate or stop the adverse effects.
What is a Security Breach?
A security breach, as defined by NIST, refers to a specific type of security incident in which an individual gains unauthorized access to systems, data, or networks, typically with malicious intent. It is a more severe subset of incidents, as a breach usually results in the exposure or compromise of sensitive data.
A breach could involve unauthorized access, data exfiltration, or the manipulation of critical systems. A breach often results in a significant loss—whether that’s intellectual property, personal data, or a company’s reputation. In other words, all breaches are incidents, but not all incidents are breaches.
Example of a Security Breach:
- A hacker gaining access to a company’s customer database and stealing sensitive personal information.
- An employee intentionally copying company data and selling it to a competitor.
- A breach in a cloud system that exposes private healthcare data.
Security breaches are the most severe of the three categories, as they can have legal, financial, and operational consequences. Organizations often have strict regulatory obligations to report breaches, especially if sensitive information such as personal health data or financial details is involved.
How Event, Incident, and Security Breach Relate
- Event → Incident → Security Breach
- An event could be the first signal of potential malicious activity. It’s logged and monitored.
- If a suspicious event occurs, it may lead to an incident, where there’s a breach of policy or security practices, such as malware activity or unauthorized access.
- If the incident leads to a compromise of sensitive data or systems, it escalates to a security breach.
It’s important to note that not all incidents result in a breach, and not all events lead to incidents. For instance, an event like logging in at an unusual hour may initially seem harmless, but if the system detects abnormal behavior or a malicious payload, that could evolve into an incident. If sensitive data is exfiltrated, the incident escalates into a breach.
Wrap Up
Understanding the differences between an event, incident, and security breach is critical for organizations looking to build a comprehensive security posture. By recognizing and responding to events early, organizations can prevent many incidents from escalating into security breaches, thereby protecting their data, systems, and reputation.
The NIST definitions serve as an important framework for distinguishing between these key cybersecurity occurrences, allowing teams to take the appropriate actions at each stage of a potential threat. Organizations should continuously monitor for events, have clear processes in place to respond to incidents, and ensure they’re prepared to manage the fallout of a security breach.
By classifying events, incidents, and breaches properly, organizations can enhance their overall risk management strategies and ensure they are better equipped to handle cybersecurity threats in a timely and effective manner.