What is Security Information and Event Management (SIEM)
Security Information and Event Management (SIEM) is a cybersecurity solution that can identify, analyze and mitigate security threats by collecting and correlating real-time and historical data from multiple sources within an infrastructure. The data typically includes the logs and events generated by firewalls, Intrusion Detection Systems (IDSs) and network devices.
SIEM combines the capabilities of two solutions: Security Information Management (SIM), which is used for collection and storage of security events, and Security Event Management (SEM), which is used to analyze security events to identify anomalous or suspicious behavior. By doing so, SIEM enables organizations to detect and respond to threats more effectively.
Traditional SIEM solutions were limited in their ability to detect threats. They could only perform static analysis of security data based on pre-defined metrics and triggers.
However, modern SIEM solutions have incorporated artificial intelligence (AI) to also analyze user behavior for anomalies that may indicate potential threats. This is a significant improvement over traditional solutions, as it allows them to detect advanced, dynamic attacks that are not easily identified by static analysis of logs or events.
For example, an AI-powered SIEM solution can identify a user who suddenly accesses several sensitive files, or someone who tries to move customer data out of a safety zone. They may also respond to the threat by alerting an administrator, or by taking an automated action, like blocking the user's access.
What are the core SIEM capabilities?
The key features of a typical SIEM solution are:
- Centralized data storage: SIEM solutions can collect logs, events and other security data from various sources, and store it inside a centralized data repository.
- Event correlation and threat detection: They can
contextualize and correlate seemingly unrelated security data to identify
complex attack patterns and potential breaches. For example, consider the
following:
- The firewall logs show that a user added a rule to allow inbound and outbound traffic to a suspicious IP address.
- The syslog shows that in the next few seconds, the same user exploited the new firewall rule to send hundreds of requests per second to a web application.
- The web application logs show that the application crashed soon afterwards.
- Incident response: An SIEM solution can automate incident response, which enables timely mitigation of potential threats. For example, in our web application attack scenario, the SIEM solution may undo the user’s actions and block their account.
- Reporting: Most SIEM solutions also offer user-friendly dashboards for visualizing security data and insights. This can help organizations in understanding their security posture and identifying areas for improvement.
A SIEM solution can establish the connection between the three example events by detecting that they involved the same user and occurred in the same time span. It may then be able to conclude that the user is trying to attack the web application.
The specific response capabilities vary depending on the SIEM solution. However, some common examples are:
- Blocking user accounts to prevent an attacker from accessing the system
- Isolating the system to prevent lateral movement
- Deleting the attacker’s tools and payloads from the system
- Restoring the system to a known good state
How does SIEM work?
Here’s what a typical SIEM workflow looks like:
- The SIEM tool starts by aggregating data from multiple sources.
- It then normalizes the collected data, i.e., converts it into a standard format. Normalization is essential for effective correlation and contextualization of multi-source data.
- The data is then stored in a centralized store, like a data lake or a warehouse
- The SIEM tool correlates events to detect threat patterns. Besides historical data, the SIEM tool also considers real-time security events and network traffic.
- It also uses machine learning to establish baselines of normal user behavior. Any deviations from these baselines are flagged as potential security threats.
- If the SIEM tool detects a potential threat, depending on its severity, the tool can either respond to the threat on its own, or provide security teams with the necessary context and data, so that they can take steps to contain it.
SIEM vs CSPM
SIEM and Cloud Security Posture Management (CSPM) are both important security tools, but they serve different purposes.
SIEM focuses on aggregation and analysis of security events to detect and mitigate threats and breaches in any IT infrastructure.
On the other hand, CPSM focuses on scanning cloud infrastructures for any security gaps, misconfigurations or vulnerabilities.
The following table outlines the key differences between the two technologies:
- Can be used for on-premises, cloud or hybrid infrastructures
- Primarily used for cloud environments
- Firewalls, IDS, routers etc.
- Cloud configurations
- Threat detection, incident response, improvement of security posture, reporting
- Compliance, improvement of cloud security, avoid misconfigurations
Why is SIEM security important?
Cyber threats have become more diverse, potent and elusive than ever before. From advanced malware and zero-day vulnerabilities to targeted ransomware attacks, malicious actors are constantly developing new strategies to bypass traditional security measures.
To navigate this ever-evolving cybersecurity landscape, organizations need solutions like SIEM that offer protection against even the most advanced cyberattacks. By analyzing historical and real-time logs, SIEM tools continuously expand their knowledge and detection capabilities, staying one step ahead of cybercriminals.
SIEM vs CIEM
SIEM and Cloud Infrastructure Entitlement Management (CIEM) are both security solutions that collect and analyze data. However, they differ in their scope, offerings and use cases.
SIEM collects and analyzes security data from various sources to detect threats and prevent breaches.
In contrast, CIEM is a cloud-focused solution used for managing cloud entitlements. It scans cloud environments for misconfigurations and vulnerabilities and provides insights into how cloud resources are being used.
The following table outlines the key differences between SIEM and CIEM:
- Can be used for on-premises, cloud or hybrid infrastructures
- Designed for cloud environments
- Firewalls, IDS, routers etc.
- Cloud services and IAM solutions, like Privileged Access Management (PAM) tools
- Threat detection, incident response, improvement of security posture, reporting
- Managing entitlements, continuous monitoring, policy enforcement, reporting
What are the benefits of deploying SIEM?
Here are some key benefits of using SIEM to protect your infrastructure:
- Threat mitigation: By analyzing real-time and historical data, SIEM solutions can stop malicious actors in their tracks. This helps minimize potential downtime due to breaches and ensures that critical data and applications stay protected.
- Incident response: When a security incident does occur, SIEM solutions can help deliver a swift response and reduce the extent of damage caused by the incident. For example, if a threat actor manages to gain unauthorized access to a database, a SIEM solution can stop them before they steal or encrypt the data.
- Achieve compliance: SIEM tools can pave the way to compliance with different regulatory frameworks, like HIPAA or PCI DSS, by improving an organization’s overall security posture.
- Protect against insider threats: By leveraging advanced behavioral analytics, SIEM can detect suspicious behavior of employees or contractors, and help prevent insider attacks.
- Formulate better security strategies: SIEM provides organizations with actionable insights derived from the analysis of large volumes of security data. These insights enable security teams to create better security policies and enforce stricter security controls.