SIEM-log - definition & overview

A SIEM log refers to the log data generated by Security Information and Event Management (SIEM) systems. SIEM logs consist of detailed records of security events and activities collected from various sources within an organization's network, such as servers, applications, firewalls, intrusion detection systems and endpoints.

SIEM logs contain valuable information about user activities, system events, network traffic and a potential security incident or security threat. By aggregating, correlating and analyzing SIEM logs, security teams can gain insights into security threats, detect anomalous behavior and respond to incidents effectively. SIEM logs are critical in enhancing threat detection, incident response and overall security posture within an organization.

The key difference between SIEM vs. log management systems is their treatment and functions concerning event logs or log files.

A log file is a file that contains records of events that occurred in an operating system, application, server or from a variety of other sources. Log files are a valuable tool for security analysts, as they create a documented trail of all communications to and from each source. When a cyber-attack occurs, log files can be used to investigate and analyze where the attack came from and its effects on the IT infrastructure.

Log parsing is a powerful tool SIEM uses to extract data elements from raw log data. Log parsing in SIEM allows you to correlate data across systems and conduct analysis to understand every incident. The log source for SIEM includes log and event files leveraged by SIEM, including logs from events that occur in an operating system, application, server or other sources.

A log management system (LMS) is a software system aggregating and storing log files from multiple network endpoints and systems in a single location. LMS applications allow IT organizations to centralize all their log data from disparate systems into a single place where an IT security analyst can view and correlate them.

A SIEM software system incorporates the features of three types of security tools into a single application.

1. Security Event Management (SEM) tools are similar to LMS. They include functionality for aggregating log files from multiple systems and hosts, but they are geared toward the needs of IT security analysts instead of system administrators.
2. Security Information Management (SIM) software tools collect, monitor and analyze data from computer event logs. They typically include automated features and alerts triggered by predetermined conditions that might indicate that the network is compromised. SIM tools help security analysts automate the incident response process, reduce false positives and generate accurate reports on the organization's security posture.
3. Security Event Correlation (SEC) software sifts through massive amounts of event logs and discovers correlations and connections between events that could indicate a security issue.

A SIEM solution combines all of these functionalities into one application that acts as a management layer above existing security controls. SIEM tools collect and aggregate log data across the IT infrastructure into a centralized platform where security analysts can review it. They also deliver SIM features, such as automation and alerts and the correlative capabilities of SEC tools.

SIEM monitoring differs from log management in treating log files and focuses on monitoring event logs. With a focus on monitoring and analysis, SIEM monitoring leverages features such as automated alerts, reporting and improving your incident response processes.

Log management systems are very similar to SIEM tools, except that while SIEM tools were purpose-built for cyber security applications, LMS tools are more geared towards the needs of someone in a systems analyst role who might be reviewing log files for a purpose besides maintaining security.

If your sole requirement is to aggregate log files from various sources into one place, a log management system might be the simplest and most effective solution for you. If your job is to maintain the security of a complex and disparate IT infrastructure using the most cutting-edge security monitoring tools available, you should be looking at SIEM software.

We can describe the difference between SIEM and log management tools in terms of the core features offered by each application. Log management tools are characterized by the following:

Log data collection - LMS aggregates event logs from all operating systems and applications within a network.

Efficient retention of data - Large networks produce massive volumes of data. LMS tools incorporate features that support efficient retention of high data volumes for required lengths of time.

Log indexing and search function - Large networks produce millions of event logs. LMS systems have tools like filtering, sorting and searching that help analysts find the necessary information.

Reporting - The most sophisticated LMS tools can use data from event logs to automate reports on the IT organization's operational, compliance or security status or performance.

SIEM tools typically have all of the same features as LMS tools, along with:

Threat detection alerts - SIEM tools can identify suspicious event log activity, such as repeated failed login attempts, excessive CPU usage, and large data transfers, and immediately alert IT, security analysts, when a possible IoC is detected.

Event correlation - SIEM tools can use machine learning or rules-based algorithms to draw connections between events in different systems.

Dashboard - SIEM tools include dashboard features that enable real-time monitoring. Dashboards can often be customized to feature the most important or relevant data, increasing the network's overall visibility and enabling live real-time monitoring by a human operator.

Sumo Logic offers cutting-edge security analytics functionality, helping organizations secure their hybrid cloud environments with incident response and threat detection capabilities and enhanced forensic investigations. Learn more in our ultimate guide to modern SIEM.

How can a SIEM solution enhance threat detection through log analysis?

A SIEM solution can enhance threat detection and response by consolidating and analyzing log data from various sources, such as application logs, system logs, security logs and endpoint logs. This unified view of log data allows for real-time monitoring of security events, anomaly detection and correlation of incidents across the network.

By applying advanced analytics and machine learning algorithms to log data, a SIEM tool can identify patterns indicative of potential security threats, enabling a security team to respond proactively to suspicious activity. Furthermore, a SIEM platform enables automated alerting and response mechanisms based on predefined rules and behavioral analytics, strengthening the organization's overall security posture and minimizing the dwell time of threats within the network.

What role do security analysts play in optimizing security posture through SIEM log management?

Security teams can utilize syslog servers for log file management by centralizing the collection, storage and analysis of log data from various devices and applications in a network. By configuring devices to send their logs to a centralized syslog server, security teams can ensure that all relevant log information is aggregated in one location, allowing for easier monitoring and analysis.

A Syslog server also provides features such as log rotation, archiving and search capabilities, enabling security teams to efficiently manage and access historical log data for investigations and compliance. Additionally, a syslog server can support secure log transfer protocols to safeguard the integrity and confidentiality of log files, ensuring that sensitive information is protected from unauthorized access or tampering.

How can using a SIEM platform for log analysis and security monitoring help organizations meet compliance requirements?

SIEM platforms help organizations ensure compliance by centralizing and correlating log data from various sources to provide a unified view of security events. By proactively monitoring and analyzing logs in real-time, SIEM solutions can detect and alert potential compliance violations, unauthorized access attempts or security policy breaches. SIEM platforms can also generate detailed reports and audit trails based on log data, facilitating compliance audits and demonstrating adherence to regulatory standards such as GDPR, HIPAA, PCI DSS and others.

Additionally, SIEM tools offer features such as log retention policies, data encryption and access controls to safeguard log data integrity and confidentiality, thereby ensuring that organizations meet stringent compliance requirements related to data protection and information security. By leveraging SIEM platforms for log analysis and security monitoring, organizations can establish a proactive approach to compliance management and demonstrate a robust security posture to regulatory authorities and stakeholders.