What is a SIEM?

SIEM technology was originally developed in the early 2000s to help organizations comply with requirements of the Payment Card Industry Data Security Standard (PCI DSS). The new solution, whose name was coined by the analyst firm Gartner, combined security information management (SIM) and security event management (SEM). Its initial purpose was log management. Today, most SIEM systems incorporate user and entity behavior analytics (UEBA) and security orchestration, automation, and response (SOAR), as well as other advanced security analytics, artificial intelligence (AI), and machine learning (ML) capabilities.

According to Gartner, SIEM solutions are continuing to evolve as cloud-based tools and solutions are adopted by enterprise IT and security teams.

By the way, SIEM is pronounced “sim.”

A SIEM collects historical and real-time security events and alerts, as well as log data, from mobile devices, servers, network components, and security tools like firewalls. They examine all collected data, identify threats, and assign a risk level to each one to help security analysts manage threat activity, triage alerts, and prepare responses. Security analysts use the SIEM’s centralized dashboards to review all security-related data from a single pane of glass, which makes it easier to spot anomalies and unusual patterns.

An important function of SIEM technology is supporting compliance and auditing by storing data, generating reports tailored to the specifications of different regulations, verifying compliance data, and detecting compliance violations.

In a nutshell, SIEM technology helps organizations see the “big picture” by pulling together disparate data points from across the entire IT environment and combing through them to identify anomalies and potential threats. By correlating and analyzing all this real-time data, the SIEM handles a task that would be overwhelming for security staff using manual processes. In other words, it empowers people to stay on top of – and make sense of – constantly changing security inputs so they can protect the organization more proactively and effectively.

Therefore, a SIEM’s importance stems, in part, from augmenting the capabilities of security teams, which are typically understaffed and overworked. While a SIEM adds value to the security operations and compliance functions, it also takes a welcome bite out of their long list of routine tasks, and can simplify complex, time-consuming processes like audit preparation.

Another aspect of SIEM’s importance is business performance. SIEM solutions help strengthen overall security posture to prevent business interruptions caused by threat actors, preserve business continuity, and contribute to organizational resiliency – especially in the face of ever-increasing cyber threats.

Here are other reasons why SIEM is an important addition to the security stack:

• Early detection: By collecting and analyzing system logs and data from across the entire IT system, a SIEM solution brings together different components of an attack that have been detected on separate devices and systems. This aggregated data enables the SIEM to determine an attack’s progression and give early warning to security teams.

• Accelerated response: SIEM capabilities, including prioritized alerts, give security teams a critical head start in responding to threats. The faster the response to incidents, the greater the chance of limiting the scope of an attack and preventing or mitigating damage.

• Containment: Using data from different devices, logs, and components, a SIEM can detect lateral movement of an attacker across the network, using IP addresses, credentials, and machines to target key assets. Understanding this lateral movement enables IT teams to take appropriate action to stop it.

The primary functions of a SIEM system are improving network visibility and event correlation, automating manual processes associated with threat detection and incident response, and generating reports to strengthen compliance and auditing.

At a basic level, SIEM solutions aggregate, sort, parse, analyze, and store data from event logs and other sources, identify deviations from normal, and take appropriate action. To “connect the dots” among all this data, a SIEM system can use rules or a statistical correlation engine.

Following are the major steps in the process:

• Data collection: SIEM systems use agents and direct methods like API calls to collect data from across the IT infrastructure, including cloud environments. This data is pulled from event logs, servers, domain controllers, endpoints, SaaS applications, cloud workloads, network traffic, security hardware and software, and storage locations.
• Data aggregation and normalization: For ease of use, the collected data is aggregated and normalized to a common format. SIEM tools can also enrich data with context to make it more useful to analysts. This data is stored in a central repository, such as a data lake or data warehouse, to assist with forensic investigations, audits, and historical analysis.

• Data analysis: SIEM solutions categorize deviations from the norm, such as “failed logon” or “account change.” Deviations prompt the tool to generate an alert or suspend the unusual activity. SIEM products also continuously monitor and analyze aggregated data in real time to identify atypical patterns or behaviors that could indicate security threats. By correlating apparently unrelated events, the SIEM system can reveal hidden threats and risks. This analytical process replaces time-consuming and error-prone manual monitoring.

• Incident response: In the case of a cyber incident, SIEM systems help security teams accelerate their investigation and response by issuing alerts, correlating events, and providing details about potential threats. SIEM tools may permit alerts to be prioritized based on the severity of the threat. They typically integrate with other security tools, such as incident response platforms, to streamline remediation.

• Reporting: Many organizations implement SIEM solutions to help with regulatory compliance and auditing. These solutions can generate customizable reports based on pre-built templates for different regulations, such as PCI DSS, HIPAA, and the GDPR. In this way, SIEM can streamline resource-intensive compliance and auditing processes.

The newest iterations of SIEM technology offer capabilities that extend far beyond the original tools’ core function of event log management. Following are additional capabilities of current SIEM products:

Cloud security: As more organizations extend their IT infrastructure to public and private clouds, they need SIEM solutions that can provide visibility and threat detection for SaaS applications and cloud-hosted data and workloads.

Threat intelligence feeds: Integration of threat intelligence feeds with a SIEM solution allows organizations to cross-reference internal data with external threat data. This capability is especially useful for threat hunting and for providing insights into attackers’ tactics, techniques, and procedures (TTPs) during incident response.

Data enrichment: A SIEM tool’s ability to convert data into insights and intelligence can improve threat detection and accelerate incident response. Security event data can be enriched with contextual information from other sources, such as user directories, asset inventory tools, geolocation tools, external threat intelligence databases, and peer grouping.

Analytics: Real-time analytics enable a SIEM tool to detect and prioritize events or activities that may pose a threat or compliance issue. Batch analytics enable the solution to identify and correlate signals in data that have not been detected in real time.

Incident prioritization: Faced with millions of daily log entries, security teams depend on their SIEM to minimize false positives and winnow down the data to notable events exhibiting abnormalities or aberrations. This process of elimination helps optimize scarce security resources and facilitate incident response.

User entity and behavior analytics (UEBA): Tracking and monitoring user behavior is an important SIEM capability. UEBA applies machine learning and statistical analysis to large data sets in SIEM systems. By modeling typical and atypical behaviors, the solution can assign risk scores to humans, machines, and corporate entities.

Security orchestration, automation, and response (SOAR): Integrating SOAR capability into a SIEM tool brings together two complementary solutions. SOAR adds automation and coordination to SIEM’s real-time event monitoring and alerting. By automating actions in response to SIEM alerts, SOAR relieves security teams of the time-consuming task of manually investigating each one.

By helping to strengthen your security posture, a SIEM solution can deliver benefits for your business as well as your security team. A robust SIEM product can help your organization achieve its current and future security goals with fewer staff, lower costs, and greater speed.

Let’s start with the bottom line: preventing or mitigating cyberattacks that can harm your reputation, customers, operations, or financials. SIEM technology makes it easier for your security team to identify a wide range of internal and external threats that other security tools might overlook. It also provides context that assists in distinguishing threats from simple anomalies. If an attack occurs, SIEM can help deliver a fast response to contain the damage. For instance, a SIEM system can stop a malicious actor who has accessed a database from exfiltrating or encrypting sensitive information.

Following an incident, the SIEM solution can enhance computer forensic investigations by allowing security teams to easily collect and analyze data. Based on this stored data, they can perform root cause analysis, recreate past incidents, evaluate new ones, and understand how to improve security measures.

Here are other business advantages provided by a SIEM tool.

Visibility: Especially as enterprises grow in size, scope, and complexity, it is difficult to achieve visibility into all areas of the IT infrastructure. SIEM solutions collect data from the entire network, including less-visible components such as third-party devices and cloud-hosted assets, which might be exploited by threat actors. A SIEM tool not only aggregates all this data into a single view, but it also stores it for future retrieval and reference.

Strategy: Based on analysis of huge data volumes, a SIEM solution can reveal patterns, vulnerabilities, and correlations that help security teams strengthen and enforce security policies and controls.

Efficiency: A SIEM system’s central dashboards provide a unified view of system data, alerts, and notifications that helps security teams collaborate efficiently when identifying and responding to threats and incidents. Another aid to efficiency is identification of significant alerts linked to actual threats, helping reduce the amount of time analysts spend on checking out false positives.

Speed: By automating critical initial stages of the incident response process, SIEM systems help SOC teams reduce metrics such as mean time to detection (MTTD) and mean time to respond (MTTR). For example, alarm prioritization enables a faster response to high-risk threats.

Compliance: Reporting capabilities help organizations in highly regulated industries comply with data privacy and security requirements. A SIEM’s data storage capabilities help meet retention mandates for compliance and auditing.

Cost reduction: SIEM solutions can help reduce security management costs by allowing security teams to do more with fewer people. They can also avoid the financial impacts of security incidents, such as ransomware demands, system downtime, and remediation expenditures.

Employee satisfaction: Automation enables security professionals to offload routine, mundane, or repetitive tasks, avoiding burnout and freeing them to focus on work that requires their unique insights and expertise and contributes to the organization’s strategic security goals.