What is SIEM (Security Information and Event Management) - A Complete Guide

Imagine you are the owner of a small but bustling neighborhood coffee shop. You have a steady stream of customers coming in throughout the day, and your primary goal is to ensure their satisfaction and maintain a safe environment. To achieve this, you need to keep an eye on various aspects of your business, such as the quality of your coffee, the cleanliness of the shop, and the behavior of both customers and employees.

One day, you notice some unusual activity in your coffee shop. Customers are complaining about their personal information being compromised, credit card fraud, and even instances of theft. You suspect that someone with malicious intent is causing these issues, but you're not entirely sure who or how.

To tackle this problem, you decide to set up a comprehensive surveillance system throughout your coffee shop. Additionally, you hire security experts who are trained to analyze the footage and respond to incidents promptly.

Now, expand this view to any type and size of business, from small and medium to multinational corporations. Such a comprehensive security-oriented surveillance system is collectively referred to as SIEM, which is an acronym that we’ll unpack.

In this comprehensive guide therefore, we define SIEM, learn how it works, its essential components and the future.

What is SIEM? 

First, SIEM is an acronym that stands for Security Information and Event Management. So then, what is Security Information and Event Management? 

Security Information Information and Event Management (SIEM) is a cybersecurity surveillance solution that enables organizations to collect data which is then used to detect, analyze, and respond to threats before they cause harm to the business.

To understand it better, let’s revisit the coffee shop example. The events captured by the coffee shop surveillance system are  analyzed and the outcomes of the analysis inform the appropriate action. 

So just like the system in the coffee shop, SIEM software collects and analyzes data from various sources, such as network devices, servers, applications, and security devices. It acts as a centralized platform that aggregates and correlates data from multiple security sources, allowing security analysts to have a comprehensive view of the organization's security posture. It helps identify security incidents, detect anomalies, and generate alerts when potential threats are detected. 

Like the security personnel in the coffee shop who review the footage, investigate incidents, and take necessary actions, security analysts using SIEM will analyze the data, investigate security events, and respond to potential cyber threats.

It’s also important to mention at this point that SIEM actually combines two programs: Security Information Management (SIM) and Security Event Management (SEM).

• SIM typically emphasizes the long-term storage, analysis, and reporting of security-related data for compliance management, forensic investigations, and trend analysis purposes. 
• SEM, on the other hand, primarily focuses on real-time monitoring and immediate response to security events as they happen.

When these two are combined, the result is a comprehensive system (SIEM) for managing the security of the organization. 

A SIEM report published in 2022 by Core Security demonstrated that 60% of organizations that use a SIEM platform are confident in their security posture. In terms of importance, 80% said that SIEM is extremely important for security.  This strong show of confidence can only mean that SIEM is indeed the go to security approach for majority organizations.

How SIEM works

As pointed above, SIEM tools work by collecting and aggregating data from various sources such as network devices, servers, applications, and security systems. They analyze this data using correlation techniques and predefined rules, to identify security incidents, anomalies, and potential threats. 

The SIEM  system generates alerts and notifications based on detected events. These alerts and notifications allow security analysts to investigate and respond promptly.

To do all this, there are certain essential components that all SIEM tools must possess. 

The essential components of a typical SIEM Solution

A SIEM solution should have the following major components: 

1. Log management

This is the process of collecting, storing, analyzing and normalizing the logs that are generated by systems and devices within the IT infrastructure. 

Logs contain valuable information about events and activities such as:

• User logins and logouts
• System and application configurations
• Network traffic
• File access and modifications
• Security policy violations
• Firewall events
• Intrusion detection system alerts
• Antivirus scans, and more. 

When examined, these logs give a powerful starting point from which the security team can identify suspicious or malicious activities, track network vulnerabilities, detect unauthorized access attempts, and gain insights into the overall security posture. 

2. Event analytics

This focuses on examining and interpreting the security events and logs above to extract meaningful insights. 

Advanced algorithms come into play here, in addition to correlation techniques, and contextual information. The ultimate goal is to spot patterns, anomalies, and signs of compromise in various data sources. 

For example, if a SIEM solution detects multiple failed login attempts from different IP addresses within a short time frame, this may indicate a brute-force attack — where the attacker systematically attempts all possible combinations of passwords or encryption keys to gain unauthorized access to a resource. 

3. Real-time monitoring

A SIEM solution should be able to monitor events and incidents all the time. This is the only way you can always ensure timely response and mitigation, which carries the advantage of reducing the potential impact of threats.

For instance, if the SIEM system detects a sudden spike in network traffic to a specific server and alerts the security team in real-time, they can quickly investigate and identify a possible distributed denial-of-service (DDoS) attack. The timely identification will allow them to take immediate measures to mitigate the attack. This way, they minimize the impact on the targeted server and the overall network.

4. Security alerts

After collecting, monitoring and analyzing events and threats, the SIEM system should raise alerts on possible dangers and their location. 

Contained in the alerts is information such as the source IP address, the targeted system, and the type of attack. Based on these alerts, security teams are able to respond quickly, investigate the incident, and implement appropriate countermeasures.

Using SIEM: From Planning & Deployment to Maintenance

These 6 steps are fundamental to getting started, implementing, using and maintaining SIEM.

1. Plan and design

What do you want to achieve with the SIEM system? This could include improved threat detection, faster incident response, or compliance monitoring.

Next is to identify the data sources that will be integrated with the SIEM system, such as network devices, servers, applications, security tools, and endpoints.

Define the log collection strategy, including the types of logs to collect, log retention policies, and log storage requirements.

Determine the correlation rules, alerts, and response actions that align with your security requirements as well as incident response procedures.

2. Deployment and configuration

1. Install and deploy the SIEM solution based on the vendor's instructions and recommended architecture.
2. Configure the system to collect and aggregate logs from the identified data sources. This may involve installing agents or configuring log forwarding mechanisms.
3. Set up event correlation rules and alert thresholds based on your security policies. Define which events should trigger alerts and which events require further investigation.
4. Integrate the SIEM system with external threat intelligence sources to enhance its detection capabilities.
5. Configure user access controls and permissions to ensure that only authorized personnel have access to the system and its data.

3. Data collection and normalization

1. Ensure that logs from all relevant sources are being collected and sent to the SIEM system. Monitor the data ingestion process to identify any issues in log collection.
2. Normalize the collected logs to a common format to facilitate consistent analysis and correlation. For example, you need to map different log formats and fields to a standardized format within the  system.

4. Monitoring and analysis

1. Monitor the system continuously for alerts and events. Investigate and prioritize alerts based on their severity, potential impact, and relevance to your environment.
2. Analyze correlated events and logs to identify patterns, anomalies, or potential security incidents. Take advantage of the SIEM's search and filtering capabilities to perform in-depth investigations.
3. Utilize dashboards and reports provided by the system to gain visibility into security events, trends, and compliance posture.
4. Leverage user behavior analytics (UBA) capabilities to detect insider threats, compromised accounts, or abnormal user activities.

5. Incident response and remediation

1. Develop incident response procedures and playbooks that outline the steps to be taken in the event of a security incident.
2. When an alert or incident is detected, follow your established incident response procedures. Determine the scope and impact of the incident, contain the threat, and initiate appropriate response actions.
3. Document and track the incident within the SIEM system, including the actions taken, evidence collected, and remediation steps implemented.
4. Conduct post-incident analysis and learn from each security incident to enhance future threat detection and response capabilities.

6. Ongoing maintenance and optimization

Review and update correlation rules, alerts, and response actions to ensure they remain relevant in your evolving threat landscape. Do this on a regular basis. 

Keep the system up to date with the latest patches and updates as provided by the vendor.

Perform periodic reviews and audits of the system's configuration, log sources, and user access controls to maintain optimal security and compliance posture.

Why invest in SIEM: The benefits

Measuring a quantifiable return on investment (ROI) for certain IT investments, such as SIEM, can often be challenging. However, the key aspect of investing in these technologies lies in understanding that tangible returns, such as revenue, may not be the primary expectation. 

Instead, the focus should be on the ability of these technologies to mitigate potential disasters for your organization. This perspective holds particular significance in the modern business landscape, where cyber attackers target businesses of all sizes, including small enterprises. 

For instance, if your business processes credit card data, it is crucial to recognize the constant high risk of compromising this data. Imagine waking up one day to discover that hackers have stolen your customers' credit card information; such an incident could severely damage your business. But with a reliable SIEM system, you can effectively prevent such risks.

In this case, the return on investment lies in the absence of the potential disaster that would have occurred if your organization did not employ a SIEM system. Therefore, the evaluation should be based on the system's ability to safeguard against these threats and potential losses.

With this background, here are the benefits of SIEM: 

1. Centralized log management

As SIEM enables centralized collection, storage, and analysis of security event logs from various sources, security teams get comprehensive visibility into the company’s network. This is important because they are then able to manage security events much more efficiently.

2. Real-time threat detection

This is a powerful advantage that SIEM brings to organizations. Imagine a tool that is constantly watching over your entire IT environment, constantly issuing alerts as issues arise. SIEM makes it possible for organizations to adopt a proactive approach, which helps prevent threats instead of reacting to problems after they occur.

3. Compliance and regulatory requirements

You can present the reports generated by SIEM as evidence during audits related to regulations such as PCI DSS, HIPAA, SOC or GDPR. This verifiable evidence will showcase your organization's commitment to security controls and adherence to standards.

4. Log retention and forensic analysis

SIEM systems are designed to allow for long-term storage of security event logs, which facilitates historical analysis and forensic investigations. This capability is valuable for identifying the root causes of security incidents, understanding attack vectors, and improving your security posture over time.

5. Operational efficiency and resource optimization

Since the collection, correlation, and analysis of logs is automated, SIEM systems automatically reduce the manual effort required for security monitoring. This leads to improved operational efficiency. The outcome of this is that security teams can focus on critical tasks and allocate resources efficiently.

6. Scalability and flexibility

SIEM solutions are designed to handle large volumes of security events from diverse sources. This makes them scalable for organizations of all sizes. They can adapt to changing security requirements and integrate with the existing security infrastructure within different contexts. You can customize and deploy them in a way that fits your unique environment and needs.

7. SIEM enhances transparency in monitoring 

With remote work and BYOD becoming prevalent, SIEM brings the much needed transparency into monitoring efforts. A good SIEM system can monitor user behavior, detect anomalous activities, and identify potential insider threats or compromised accounts.

The future of SIEM  

One issue that has consistently concerned companies that have deployed SIEM is false positives. False positives refer to the incidents or alerts generated by the system that are incorrectly identified as security threats or malicious activities. 

Because of such challenges, SIEM is constantly pitted against the newer approach known as SOAR (Security Orchestration, Automation and Response). 

Another area that SOAR is viewed to be performing better than SIEM is the provision of actionable measures for issued alerts. In other words when looking at the alerts, security teams should also be able to see what it is they need to do to solve the problem. They should not be left in the dark. 

These are some of the key challenges that the future of SIEM needs to address. Every indication is that this future ultimately lies in Artificial Intelligence. Since cyber hackers learn to bypass security programs with advanced protocols, next-generation SIEM solutions should incorporate adaptive AI programs for more combative power. 

Besides fixing the current shortcomings of SIEM, these adaptive AI programs can continuously learn and adapt to evolving attack techniques. As a result, SIEM systems will be able to dynamically adjust their detection algorithms and improve accuracy over time. 

With the ability to analyze vast amounts of data and identify subtle patterns, AI-powered SIEM solutions will be able to proactively detect sophisticated and unknown threats, thus challenges such as false positives and response times.