What is SIEM?
Security information and event management (SIEM) is critical for enterprises to proactively identify, manage, and neutralize security threats. A SIEM solution employs mechanisms such as event correlation, AI-driven anomaly detection, and machine learning-powered user and entity behavior analytics (UEBA) to detect, scrutinize, and counteract cybersecurity threats. These capabilities enable SIEM systems to provide real-time security alerts and enhance an organization's ability to respond to incidents rapidly and effectively.
Evolution of SIEM
In 2005, Gartner® coined the term SIEM, combining security information management (SIM) and security event management (SEM).
- Evolution of SIEM
- How SIEM works
- Features of a SIEM tool
- SIEM solution use cases
- Benefits of using SIEM
- Next-Gen SIEM capabilities
Security information management (SIM)
SIM involves the collection and storage of all network activity-related data. This can range from log data collected from servers, firewalls, domain controllers, routers, databases, and NetFlow, to unstructured data present in the network, such as from emails.
Security event management (SEM)
SEM refers to the monitoring and analysis of security events. These are analyzed in real time using various techniques, alerts are sent, and workflows are initiated to respond to any abnormal behavior.
As cyberthreats evolve and become more sophisticated, the need for more advanced SIEM solutions is evident. Next-Gen SIEM builds upon traditional SIEM by integrating advanced analytics, UEBA, and orchestration capabilities. This allows for more proactive threat hunting, better anomaly detection, and faster incident response times.
Over the years, SIEM tools have evolved from simple log management to sophisticated threat detection and management. Today's SIEM plays a major role in advanced persistent threat detection with AI and ML capabilities such as UEBA. SIEM tools cater to security monitoring and analytics use cases of SOCs like ensuring data and cloud security, assessing and managing cyber risks, and staying compliant with regulatory mandates.Figure 1: Evolution of SIEM
How does a SIEM solution work?
A SIEM solution ingests and analyzes security-related data points from sources across the network and provides insights to security administrators for the detection and mitigation of security attacks. It works like this: Event data, such as logs and flow data, is ingested by the SIEM solution for network behavior analysis. At the fundamental level, the solution collects data generated by every device and application in the network, using both agent-based and agentless mechanisms. The solution also takes in non-event data and contextual information, such as threat feeds. Once all the data is centrally aggregated within the SIEM software, it's normalized and analyzed using correlation and ML algorithms and converted into actionable information, which is delivered to security teams in the form of notifications and interactive dashboards.
A SIEM solution's dashboards and graphical reports provide real-time insights into security events occurring across the network. These analytics dashboards help security analysts identify trends and suspicious behavior, check recent alerts, and monitor the health of the entire network.
Related SIEM resources
- Case Studies
What are the key features and capabilities of a SIEM solution?
- Comprehensive log management
- Event correlation
- Forensic analysis
- Security incident management
- Advanced threat analytics
A SIEM solution ingests log data from sources across the network, including servers, firewalls, intrusion detection and prevention systems, applications, database servers, switches, routers, Active Directory servers, workstations, and more. This aggregated log data is stored securely in a central location, facilitating easy analysis. Log collection is usually carried out using various techniques, such as agentless and agent-based log collection.
Agent-based log collection
This method requires the deployment of an agent on every device. The agent collects logs, then parses and filters them before returning the logs to the SIEM server. This technique is mainly used in a closed and secured network, such as a demilitarized zone, where communication is restricted.
Agentless log collection
This is the more frequently used method in which logs generated by devices are automatically collected by the SIEM server using a secure communication channel, such as a specific port using secured protocols.
Followed by log collection, a SIEM tool parses the logs, extracting and normalizing the data to make them suitable for effective analysis and correlation.
The primary purpose of a SIEM solution, threat detection, is achieved by aggregating and correlating the security data. The correlation engine works on rules, which are sequences of events that could indicate a security threat. A modern-day SIEM solution uses non-event data and threat feeds to enrich its correlation engine's efficiency. SIEM solutions are customizable, offering users the ability to fine-tune the correlation rules to capture threats that are specific to the enterprise. Further, the correlation ability is tied to automated workflow executions, which reduces the manual process of addressing threats that require immediate intervention.
Traffic from a malicious source should be immediately blocked by writing a rule in the enterprise firewall. A SIEM solution should not only correlate the firewall logs with the threat feeds to detect the allowed malicious traffic, but also provide the option to immediately block the traffic by writing a firewall rule or policy. This process can be made more efficient by adding more context, such as a reputation feed of the malicious source.
With a SIEM solution, security analysts can securely retain log data for extended periods of time and comb through a vast number logs efficiently. This enables them to examine a security incident to determine the extent of data leakage, identify the perpetrator of the attack, see how long the attacker was in the environment, understand the series of actions taken by them, and assess the business impact. Furthermore, the forensic team can also reconstruct past security incidents to pinpoint any security vulnerabilities and prevent future cyberattacks.
A SIEM solution gathers all detected incidents and presents the timeline and critical data points in a dashboard to monitor, triage, and resolve them from a single console. While the real-time alerting systems of a SIEM solution helps reduce the mean time to detect (MTTD), the security incident management console helps to minimize the mean time to resolve (MTTR) by offering the ability to execute mitigation steps from within the console. The incident management capabilities of a SIEM tool also ensures accountability for security professionals by providing a dashboard to track and triage the incident resolution process.
The implementation of different threat detection mechanisms—rule-based correlation, signature-based threat detection, and ML-based anomaly detection—combined with real-time security alerts enhances the ability of a SIEM solution to accurately spot threats and reduce the MTTD. Security analytics provides a platform for effective threat investigation, which is further enhanced with threat feed integrations from reliable open-source tools or third-party vendors. Implementation of a threat modelling framework such as MITRE ATT&CK further strengthens the threat hunting, detection, analytics, and remediation capabilities of a SIEM solution. This speeds up the mitigation process by allowing admins to identify threat sources quickly.
A SIEM tool's UEBA feature detects abnormal behavior in an organization network using ML and deep learning algorithms. A behavior baseline is created by collecting data related to user and entity activities in the network. When any deviation from the baseline is detected, a risk score will be assigned based on the severity. Deviations can include logons at an unusual hour, excessive logon failures within a short timeframe, privilege escalations, and more. Security administrators are notified in real time if the risk score crosses a set threshold. ML-driven UEBA captures advanced persistent threats that can often go undetected with rule-based detection mechanisms. UEBA also plays a major role in detecting insider threats, account compromises, and data exfiltration.
SIEM solution use cases
Many organizations are required to comply with regulatory mandates. A SIEM tool can simplify the entire audit process, minimizing security risks and easing compliance demonstration for enterprises by providing out-of the box, audit-ready reports for various compliance standards, such as PCI DSS, the GDPR, HIPAA, FISMA, SOX, FERPA, NERC CIP, PDPA, and more. Some SIEM solutions also enable users to customize or create new compliance reports based on their auditing requirements.
As more organizations shift to the cloud, new security challenges can emerge. Using a SIEM tool boosts visibility into cloud environments, helping organizations reduce risk and empower their defense against threats.
Cloud access security brokers (CASBs) use the organization's security policies to inspect the data transmitted between a cloud service provider and an organization. For instance, if employees store sensitive corporate data on unsanctioned cloud applications, CASBs assist IT teams in identifying all unmanaged applications accessed by users and implementing remedial measures. Integrating SIEM with a CASB offers IT admins a holistic view of cloud security, enhancing threat detection and establishing coordinated incident response.
In addition to enhancing network monitoring, SIEM solutions offer the capability to monitor user activities within an organization, enabling the detection and prevention of both intentional and unintentional insider threats. This ensures users cannot abuse their access privileges to leak sensitive information or expose network systems to external attacks. A SIEM solution provides valuable insights into user login and logoff activities, as well as tracks configuration changes and modifications made to sensitive files and folders.
What are the benefits of deploying a SIEM solution?
Compliance adherence and management
Map the requirements of various compliance regulations with security operations, and provide audit-ready compliance report templates and compliance violation alerts for various regulatory mandates.
Faster and more efficient security operations
Spot and prioritize the resolution of security threats, automate responses to known threats, and improve MTTR.
Optimized network operations
Continuously monitor all network activities and store log data for root cause analysis and troubleshooting.
Get back to business after a breach or security incident with log forensics and impact analysis, and instantly generate incident reports to avoid compliance penalties.
Integrate with other IT solutions in your network and centralize security management.
To address the ever-changing security landscape, next-gen SIEM tools provide a new set of capabilities that provide actionable intelligence that helps businesses implement proactive security strategies and improve their security posture.
Next-gen SIEM solutions offer advanced capabilities, such as:
Detecting anomalous activities across platforms
Apart from detecting anomalous activities within the perimeter network, next-gen SIEM extends this capability to various platforms to correlate events happening across the hybrid business environment.
Advanced and complex threat detection mechanisms
Adversaries employ advanced attack techniques, such as fileless malware, ransomware that steals credentials and encrypts sensitive data, and more, to compromise an enterprise network. AI-enabled threat detection capabilities and ML-based behavior profiling found in next-gen SIEM solutions helps organizations detect these sophisticated attack techniques.
Security orchestration and automation response (SOAR)
Next-gen SIEM solutions orchestrate with other critical IT infrastructure, such as IT services management, IT operations management, and more, to ensure a solid security posture. Further, automated incident response helps reduce MTTR.
Identity-driven security approach
With more organizations moving to the cloud, identities have become the new perimeter. When an identity is compromised, it makes the entire cloud and on-premises network vulnerable to attack. Next-gen SIEM solutions help secure identities by bringing in secured access, shadow IT monitoring, and user behavior profiling.
Are you looking for a SIEM solution?
ManageEngine Log360, recognized in the Gartner® Magic Quadrant™ for SIEM six consecutive times, is a unified SIEM solution with integrated DLP and CASB capabilities that detects, prioritizes, investigates, and responds to security threats. It combines threat intelligence, ML-based anomaly detection, and rule-based attack detection to identify sophisticated attacks and offers an incident management console for effectively remediating detected threats. Log360 provides holistic visibility across on-premises, cloud, and hybrid networks with its intuitive and advanced security analytics and monitoring capabilities.
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