Definition of Event Correlation
Event correlation takes data from either application logs or host logs and then analyzes the data to identify relationships. Tools that utilize event correlation can then perform actions, such as sending alerts for hardware or application failures, based on user-defined rules.
Correlation and root-cause analysis have been stalwarts of IT performance monitoring for some time. Both practices help IT departments to determine the underlying cause of a problem and resolve it quickly to minimize any business impacts and losses.
Event Correlation Use Cases and Techniques
In essence, event correlation is a technique that relates various events to identifiable patterns. If those patterns threaten security, then an action can be imposed. Event correlation can also be performed as soon as the data is indexed. Some important use cases include:
Data intelligence
Operations support
Root cause analysis
Fraud detection
You can handle events through something as simple as sys-logging, which allows you to view new events as they arrive, but event correlation is the technique that associates varying events with one another. This is often achieved with the use of event correlation tools and alerting systems. Furthermore, correlating events can help security teams identify those that are most important.
Examples of Event Correlation
While you want to monitor events, you also want to implement automated processes that can determine relationships between complex events. One example of event correlation can occur with intrusion detection.
Perhaps there is an employee account that hasn't been accessed for years, and suddenly a large number of login attempts are noticed. That account may start executing suspicious commands. Through event correlation, an intrusion detection system can send an alert indicating that an attack is in progress.
What if among the thousands of login attempts, one was successful? Correlation then comes into play by marking this event as "curious." Then, it may notice that 15 minutes earlier, a port had been scanned. Now, it may notice that the IP address of the port scan and the login attempts are the same. This is where context is added to correlation.
Then, the event is marked with an elevated concern. These are specific events that can be related to each other – out of thousands. In fact, in any scenario, this could happen within millions of events.
If you perform manual correlation, you will have to rely on luck more than skill – because you will need to add context to the data. Furthermore, you need to see how the pieces fit together to figure out the puzzle.
Another example is incident management, where hundreds of alarms are sounded conveying that servers and related services are no longer reachable. Event correlation tools can analyze the data to determine the root cause, allowing the IT department to focus on implementing a solution rather than spending valuable time trying to pinpoint the cause.
In complex, networked environments, thousands or millions of events can be generated in just a short period of time. These events can range from critical to informational. While a good analyst can identify the root cause of failures, this type of knowledge is expensive to obtain. So, event correlation technology was designed to automate and register interrelations between ongoing events, in a more cost-effective manner.
Benefits of Event Correlation
Event correlation offers full context and logical analysis through a sequence of related events. As a result, security analysts can make a thoughtful decision on what to do next to respond and investigate.
This is about turning raw data into actionable alerts, alarms, and reports with the advantage of user-defined rules. Then, the appropriate action can be executed. Some of the benefits of using event correlation techniques include:
Real time threat visibility
Active event correlation and analysis can help IT departments detect threats in real time. Failures, security breaches, and operational issues all affect business. Instead, these can be successfully avoided.
Vigilance of network safety
The network can be monitored at all times. In addition, impact failures – such as those that affect business services – can be identified and remedied.
Continuous compliance reports
Federal, state and local regulations may require varying levels of compliance with security and networked systems. Event correlation techniques can be used to ensure a constant monitoring of all IT infrastructures. Reports can then be generated to detail security-related threats and events, along with the steps needed to prevent potential risks.
Reduces operational costs
Event correlation tools automate processes such as the analysis of large work flows to reduce the number of relevant alerts. As a result, the IT department can spend less time trying to make sense of it all and more time resolving immediate threats.
Improves time management
Fewer resources are needed as contemporary event correlation tools are user-friendly and efficient. Plus, they can save a lot of time relative to using SIEM tools for event correlation and analysis.
Event correlation techniques are designed to detect events, make sense of them and assign the appropriate control action. As data becomes more complex, the need for correlation intelligence will continue to increase in significance.