Security information and event management (SIEM) is cybersecurity technology that provides a single, streamlined view of your data, insight into security activities, and operational capabilities so you can effectively detect, investigate and respond to security threats. A SIEM solution can strengthen your cybersecurity posture by giving you full, real-time visibility across your entire distributed environment — whether on-premises, hybrid or cloud — as well as providing historical analysis. SIEM technology can also help you increase overall organizational resilience across a diverse array of tools and technologies.
To detect threats and other anomalies, a SIEM (pronounced “sim”) solution ingests and combs through a high volume of data in seconds to find and alert on unusual behavior — a task that would otherwise be impossible to execute manually. A SIEM tool can also provide you with a snapshot of your IT infrastructure at any given moment, while allowing you to store and manage log data to ensure compliance with industry regulations. This ability to analyze data from all sources in real time — including network applications and hardware, as well as cloud and software-as-a-service (SaaS) solutions — can be critical to helping organizations stay ahead of internal and external threats.
SIEM technology has been around for more than a decade and has evolved considerably since Gartner coined the term in 2005. While it may not have the same buzz as AI and machine learning technologies and certain point tools, it has evolved into a solution critical for threat detection and response in an increasingly complex and fast-moving IT and security landscape.
In this article, we’ll explore the essential features and functions of SIEM technology and how to choose the right SIEM tool.
How does SIEM work?
A SIEM solution aggregates event data across disparate sources within your network infrastructure, including servers, systems, devices and applications, from perimeter to end user, and including cloud, multicloud and hybrid environments, as well as on-premises. Ultimately, a SIEM solution offers a centralized view with additional insights, combining context information about your users, assets and more. It consolidates and analyzes the data for deviations against behavioral rules defined by your organization to identify potential threats.
Data sources include:
- Network devices: Routers, switches, bridges, wireless access points, modems, line drivers, hubs
- Servers: Web, proxy, mail, FTP
- Security devices: IDP/IPS, firewalls, antivirus software, content filter devices, intrusion detection appliances
- Applications: Any software used on any of the above devices
- Cloud and SaaS solutions: Software and services not hosted on-premises
- Remote workforce: All devices and activity related to remote work
Attributes that may be analyzed include users, event types, IP addresses, memory, processes and more. SIEM products will categorize deviations as, for example, “failed login,” “account change” or “potential malware.” A deviation causes the system to alert security analysts and/or act to suspend the unusual activity. You set the guidelines for what triggers an alert and establishes the procedures for dealing with suspected malicious activity.
A SIEM solution brings together data across disparate sources within your network infrastructure
A SIEM solution also picks up on patterns and anomalous behavior, so if a single event doesn’t raise a red flag, the SIEM can eventually detect a correlation across multiple events that would otherwise go undetected, and trigger an alert. Finally, a SIEM solution will store these logs in a database, allowing you to conduct deeper forensic investigations or prove that you are meeting compliance requirements.
What are the benefits of SIEM?
SIEM technology helps security analysts see across their enterprise IT environment and spot threats that evade other means of detection. A good SIEM solution will help security analysts do their jobs better and can help an organization solve three major security challenges:
- Visibility: A modern SIEM provides real-time status updates into your security posture — retrieving and maintaining contextual data around users, devices and applications from across on-premises, cloud, multicloud and hybrid environments. This makes it easier for security analysts to spot bad actors and zero in on threats.
- False alerts: A SIEM solution can help reduce the number of false positive alerts, helping security analysts more quickly detect and investigate actual threats. Potential threats are identified, categorized and triggered via dashboards, then sent to an analyst for review.
- Flexibility: Many SIEM solutions offer support for and integrate with a wide array of environments and technologies, as well as across internal and external teams.
In all, the benefits of SIEM help enterprises prevent costly breaches and avoid compliance violations that entail hefty financial penalties.
What is a SIEM tool?
Your SIEM tool is the software that acts as an analytics-driven security command center. All event data is collected in a centralized location. The SIEM tool does the parsing and categorizing for you, but more importantly, it provides context that gives security analysts deeper insight regarding security events across their infrastructure.
SIEM technologies vary in scope, from basic log management and alerting functionality to robust real-time dashboards, machine learning and the ability to conduct deep dives into historical data for analysis. Leading solutions may provide dozens of dashboards, including:
- An overview of notable events in your environment that represent potential security incidents.
- Details of all notable events identified in your environment, so you can undertake triage.
- A workbook of all open investigations, allowing you to track your progress and activity while investigating multiple security incidents.
- Risk analysis that lets you score systems and users across your network to identify risks.
- Threat intelligence designed to add context to your security incidents and identify known malicious actors in your environment.
- Protocol intelligence using captured packet data to provide network insights that are relevant to your security investigations, allowing you to identify suspicious traffic, DNS activity and email activity.
- User intelligence lets you investigate and monitor the activity of users and assets in your environment.
- Web intelligence to analyze web traffic in your network.
How is UBA used in SIEM?
Other tools have also made their way into the SIEM space, particularly user behavior analytics (UBA). UBA, also called user and entity behavior analytics (UEBA), is used to discover and remediate internal and external threats. While UBA is often seen as a more advanced security tool, it’s increasingly folded into the SIEM category. For instance, the Gartner Magic Quadrant for SIEM includes information about UBA/UEBA offerings.
UBA works by creating a baseline for any user or application’s data, which then illuminates deviations from that norm that could mean a threat. UBA also monitors malicious behavior and preventatively addresses security issues. These functions play a critical role in any SIEM solution as they illuminate patterns of behavior within the organization’s network, and offer context around known and unknown threats. They also filter alerts before the security operations center (SOC) team is notified — helping reduce alert fatigue and freeing up analysts’ time for more complex or urgent threats.
What is SIEM’s role in the SOC?
SIEM’s role is to provide analysts in the SOC with consolidated insights from analysis of event data too varied and voluminous for manual review. SIEM analysis of machine data and log files can surface malicious activity and trigger automated responses, significantly improving response time against attacks.
While SOCs existed before SIEM came along, SIEM gives SOC analysts visibility across the entire security landscape and is a vital tool for the modern SOC’s mission to:
- Respond to internal and external attacks
- Simplify threat management
- Minimize risk
- Achieve organization-wide visibility and security intelligence
A SIEM solution can help a high-functioning SOC detect and thwart threats and proactively improve security.