What is security information and event management (SIEM)?

SIEM solutions operate in real time, collecting security data from endpoints, servers, network applications, firewalls, and cloud deployments. They aggregate information in a standardized format to deliver rapid and comprehensive updates about security events.

When properly applied, SIEM technology enhances security visibility in complex hybrid settings, cuts the mean time to detect and respond to threats, and helps meet stringent data security compliance requirements.

How does SIEM work?

Security information and event management tools collect relevant security data and present it in a form that analysts can use in threat detection and mitigation processes. SIEM solutions achieve these goals via several core features, including:

• Data gathering and log aggregation: SIEM tools collect data at strategic locations (such as firewalls, IDS systems, routers, switches, network honeypots, or IoT devices). They log security events in a normalized format, ensuring log data is consistent across all devices. This makes it intelligible to threat analysts and centralized security tools.
• Event correlation: SIEM solutions apply pre-defined rules or machine learning algorithms to detect suspicious behavior or web traffic patterns. For example, they may detect multiple failed logins on the same account from different devices. SIEM connects events logically, reducing the risk of false positives and making it easier to detect advanced persistent threats.
• Real-time threat detection: SIEM operates constantly. Monitoring systems provide real-time alerts to security teams about malware infections, suspicious user actions, or password stuffing attacks. SIEM can also monitor for zero-day exploits, leveraging threat intelligence feeds to detect emerging threats.
• Event management: When SIEM solutions detect threats, incident response processes kick in. Most SIEM platforms include forensic analysis tools to make sense of security incidents and determine the correct response. Logs also provide historical context, offering more detail about the nature of threats and their potential impact.
• Reporting functions: Data collection and logging enable seamless compliance reporting. Companies can generate reports on data protection to meet HIPAA or PCI-DSS requirements. Data is also available to assist internal security audits.

Benefits of SIEM

SIEM is a powerful suite of cybersecurity tools with numerous potential user benefits. Advantages of implementing SIEM solutions include:

• Improved threat detection: SIEM monitors traffic and behavior at critical locations. Security teams receive timely alerts about breaches of security rules or incidents identified by machine learning tools. Correlation also improves the quality of alerts, eliminating false positives and focusing on high-risk threats.
• Better cybersecurity visibility: SIEM combines data from disparate network locations. Data from endpoints, applications, and cloud deployments flows into a centralized solution. Security teams can track every device and identify policy violations like shadow IT installations.
• Faster incident response processes: Companies need quick responses to malware attacks and data theft incidents. Automated alerts identify incidents quickly, reducing dwell times for malicious attackers.
• Simplified integration with other tools: SIEM solutions generally integrate smoothly with cybersecurity tools like SOAR (Security Orchestration, Automation, and Response). Integrations enable immediate mitigation actions. They also allow analysts to launch threat hunting campaigns based on SIEM logs and outputs from EDR/XDR tools or SOAR solutions.
• Identify and mitigate advanced threats: Advanced malware evades basic security measures and embeds itself deep within networks. SIEM utilizes advanced threat detection techniques such as behavioral analytics (UEBA) alongside machine learning and threat intelligence. This helps to catch below-the-radar threats that normally pass undetected.
• More robust compliance: Modern regulations make strict demands on companies to protect user data and safeguard IT assets. SIEM helps meet compliance requirements by creating standardized and information-rich security logs. Security teams can use SIEM logs to generate reports and demonstrate compliance.
• Deeper understanding and internal audits: Companies can use SIEM solutions to analyze their network history and understand long-term patterns. Security teams can use SIEM logs in root cause analysis and use the outcomes to implement durable improvements to the organization's security posture.
• Simplification: Perhaps the most important benefit of SIEM implementation is the way it simplifies cybersecurity. SIEM aggregates hundreds of data sources within a single solution, making it easier to manage security incidents on complex networks.

Common SIEM use cases

SIEM technology has many practical uses for companies and other organizations. As the use cases below demonstrate, gathering and analyzing data about security events can strengthen cybersecurity in small and large-scale organizations alike.

Securing data against advanced persistent threats (APTs)

APTs are engineered to bypass firewalls and standard intrusion detection systems. When successful, they can reside for long periods, monitoring traffic and extracting sensitive data.

SIEM solutions cut the risk of advanced threats. Monitoring tools gather data from multiple sources to detect multi-stage attacks. SIEM detects initial intrusions, network scans, and privilege escalations by attackers. They connect activities on different devices and servers, providing reliable evidence of advanced threats before APTs take root.

Protecting networks against ransomware attacks

Ransomware is a type of malware that encrypts data or systems and demands a financial ransom before restoring control to the network owner.

SIEM can help detect ransomware attacks at an early stage by identifying unauthorized encryption activities. Detection tools also flag multiple failed logins (which often indicate a coordinated effort to breach network defenses). SIEM may also link phishing emails with malware signatures, providing clear evidence of an active ransomware threat.

Guarding against insider threats

Malicious insiders can extract valuable data, damage network infrastructure, and smooth the way for external attackers. Detecting this type of threat is challenging, as insiders usually pass authentication and authorization checks. However, SIEM provides a solution.

SIEM tools detect deviations from normal user behavior. For instance, monitoring tools generate alerts when users access (or try to access) files that fall outside their normal privileges. They may also take into account devices used by insiders, their location, or the time they log in.

Detecting phishing campaigns and educating staff

Phishing campaigns often target entire workforces. Attackers only need to harvest a few credentials from careless employees to gain network access and cause harm. Identifying and blocking suspicious emails is essential.

SIEM solutions help by monitoring email traffic and user activity. Monitoring tools look for suspicious links, unusual credential submissions to external websites, and repeated emails from unknown senders. IP filtering also blocks content from addresses flagged as malicious.

Security teams can use information generated by logs to inform employees about phishing risks and identify specific high-risk senders.

SIEM vs other cybersecurity solutions

SIEM is part of a diverse cybersecurity landscape and may not be the best solution for all organizations. Many companies combine SIEM with other tools to harness event management and advanced threat detection, and it's important to understand potential alternatives.

SIEM vs Extended Threat Detection (XDR)

XDR integrates threat detection and response by deploying agents on all endpoints, cloud services, and strategic network assets.

Casting a wide surveillance net allows XDR solutions to detect incoming attacks. AI-based behavioral scanning and advanced analytics look for hidden threats, providing real-time alerts for triage by security analysts.

SIEM focuses on data logging and analysis. SIEM provides broad, real-time detection by correlating logs from numerous disparate systems, while XDR offers deeper, more contextual detection by analyzing rich telemetry from a finite set of integrated sources like endpoints and cloud workloads.

SIEM excels in understanding historical data, managing events, and ensuring compliance. XDR allows proactive protection against advanced threats.

Many organizations combine SIEM with Endpoint Detection and Response (EDR). EDR is a stripped-down form of XDR based on endpoint detection. On its own, EDR provides limited protection. However, when combined with SIEM logging and analysis, it can be a reliable alternative to full XDR alternatives.

SIEM vs Security Orchestration, Automation, and Response (SOAR)

SOAR integrates cybersecurity tools and automates responses, reducing the risk of human error and liberating analysts to focus on high-risk alerts. SOAR implements playbooks to streamline incident response, cutting mean-time-to-respond, and ensuring consistency.

SIEM does not rely on automated responses. Instead, SIEM tools aggregate data in a normalized format to simplify threat analysis.

However, SIEM often includes automated reporting functions and can integrate seamlessly with mitigation solutions. So the distinction between SOAR and SIEM is not always clear. The two solutions complement each other to deliver robust cybersecurity.

Best practices for implementing SIEM

When implementing SIEM, companies should keep the following best practices in mind:

• Understand your objectives: Identify the use cases for SIEM. For example, you may foreground DDoS prevention or detecting ransomware attacks. Use these objectives as yardsticks to determine whether SIEM is meeting your needs.
• Inventory data sources: SIEM generally cannot automatically scan network resources and determine the best data collection architecture. Users must carefully choose data collection locations to cover critical systems. Include endpoints, firewalls, web servers, and cloud platforms.
• Define correlation rules based on critical threats: SIEM solutions must apply the right detection logic to discover relevant threats. For example, healthcare companies must correlate logs regarding employee emails, IoT devices, and data containers holding protected information. Always keep your threat environment in mind, and revisit correlation rules regularly to ensure they remain functional.
• Test and fine-tune your SIEM deployment: Think of SIEM as an evolving solution. Rules and data collection sources should change as threats and network assets evolve. Test logging and correlation processes by workshopping real-world threats.
• Integrate threat intelligence feeds: SIEM works better when tools combine local logging with global intelligence data. Integrate indicators of compromise into SIEM solutions to catch active attack techniques. Use databases of compromised websites and IP addresses. And cross-reference SIEM reports with intel to check for specific threat actors.
• Train staff to use SIEM solutions: Schedule training in SIEM fundamentals, such as log collection, correlation, and analysis. Run scenarios based on real-life security incidents, bringing in analysts, engineers, and departmental managers. Always focus on compliance goals, explaining how SIEM contributes to audits and reporting.

Improve data logging and visibility with SIEM solutions

Security Information and Event Management solutions function in real-time, logging traffic flows and user behavior. Tools gather data from many sources, converting it into a standard format and delivering it to centralized control systems.

SIEM provides comprehensive information to detect, analyze, and mitigate security incidents. This information can often identify previously unseen threats from cyberattackers and insiders. However, SIEM is generally not used alone. Companies should combine SIEM outputs with mitigation systems to streamline threat detection and neutralization.