All enterprises comprise vast webs of interconnected devices. An average company relies on hundreds of thousands of endpoint devices at any one time. The constant exchange of information necessary to sustain business depends on a network of surrounding infrastructure, such as load balancers, data storage, and APIs.
As network sizes increase, so too does the data infrastructure that supports them. The sheer amount and variety of reliant devices and networks create more opportunities for bad actors to infiltrate an organization’s network.
This article will compare two SOC technologies - Security Information and Event Management (SIEM) and Extended Detection and Response (XDR) – to see how each streamlines information processing.
What is SIEM and How Does it Work?
SIEM solutions use logs to maintain insight into a complex network of devices, firewalls, and switches. Logs contain information about a server’s internal workings. SIEM applications were the first to give security teams deeper insight into application health. Since 2005, SIEM has evolved rapidly; modern offerings aggregate and analyze log data in near-real-time. As a result, well-configured SIEMs use rules to cut through the noise of endless logs and alert security administrators to significant events. For more info, see our guide: ‘What is SIEM?’
By combining correlation rules and models, SIEM transforms data into action. Correlation rules simply tell your SIEM system what sequence of events could indicate an attack, and to notify your admin team when something doesn’t seem right.
All sorts of behavior can trigger individual rules. Composite rules analyze concerning behaviors by chaining multiple rules together. For example, your SIEM can flag 6 failed login attempts from the same IP address - but only if that IP address is trying with 6 different usernames.
An advanced SIEM tool profiles normal data traffic patterns; with composite rules, it triggers an alert if suspicious behavior pops up - such as a user switching from their normal account to a privileged one, then attempting to perform an abnormal data transfer to or from an external service. Modern SIEM platforms use data visualizations to provide a unified view of threats across most of your organization’s technology stack.
What is XDR? How Does it Work?
While SIEM tools have provided security professionals with unparalleled log visibility, many systems are incompatible with the SIEM tool. The rule-based approach also leaves security teams swamped with unimportant alerts.
An XDR solution, however, comprises several security concepts, using data from endpoints, email systems, networks, IoT devices, and applications to expand the scope of security events. Whereas Endpoint Detection and Response (EDR) systems rely on siloed traditional security measures, XDR integrates the log management approach of SIEM with several other security components to form a cohesive whole. Integrating EDR systems within XDR extends visibility into every endpoint. XDR incorporates network traffic analysis to identify even the most advanced attack patterns.
Cloud security tools are another crucial integration point for XDR systems. Integrating cloud access security brokers (CASBs) and secure web gateways into the XDR ecosystem monitors and protects cloud environments. XDR’s scope can be as wide as necessary: integrating identity and access management (IAM) solutions further provides insight into user behaviors and access patterns, to prevent identity-based attacks.
An analysis engine uses telemetry data to determine the nature of every alert. After identifying a potential threat, XDR platforms can automatically respond by isolating affected systems, blocking malicious activity, rolling back actions to a safe state, or alerting the security team. With its increased visibility, XDR provides a promising foundation for automated security responses.
These automated playbooks synthesize responses based on severity, drastically reducing response time and alert backlogs. XDR creates comprehensive cross-department information that drastically streamlines an analyst’s task, allowing them to work more strategically and effectively. If you’re still left asking ‘What is XDR?’, see our deep-dive into this new and exciting field.
SIEM vs XDR Comparison: 5 Key Differences
The differences between SIEM and XDR solutions are nuanced but important; SIEM offers a way to collect and store logs for compliance, data storage, and analysis. Traditional SIEM solutions bolt security analytics on top of existing log collection and normalization features. Without a native ability to distinguish between genuine threats and false alarms, security teams are often overwhelmed.
XDR, on the other hand, is built specifically for threat identification and to accommodate the gaps in SIEM logs. It centralizes endpoint and firewall data, rather than raw logs alone. While XDR offers organizations new security capabilities and enhanced protection, SIEM still has vital use cases outside of threat detection, such as log management and compliance.
The following table offers an in-depth XDR vs SIEM comparison.
SIEM | XDR | |
Data Sources | Log files that comprise events from a series of devices. | Endpoints, firewalls, servers, and other security tooling - including SIEM. |
Deployment Location | Data collected via data center with a dedicated SIEM appliance. | Agents on each endpoint and network appliance. Central depository is within own architecture, using vendor threat intelligence. |
Deployment Model | Storage systems require manual maintenance. Pre-integration with cloud systems and data sources allows for quicker deployment. | Automated in-house threat detection teams identify emerging threats. Manual security ops address the highest-priority threats. |
Performance and Storage Considerations | No negative performance impact. Large quantity of logs - storage required between 1 and 7 years. Syslog servers retain only essential information in a standardized format. | When monitoring east-west traffic, performance can be impacted. Depending on the organization's size, a data lake may be required for telemetry data. |
Fundamental Approach | Enables organizations to scrutinize log data from all network applications and hardware at any time. | Streamlines the collection, analysis, and remediation across the full spectrum of an organization’s security tools. |