SIEM vs. EDR: What’s the difference?

Is EDR the same as anti-virus?

No. While traditional anti-virus solutions excel at detecting known malware, they often struggle to identify advanced threats like fileless malware and zero-day exploits.

EDR is a modern evolution of anti-virus software, which is much more comprehensive and has several distinct advantages:

• Advanced threat detection: EDR solutions monitor endpoint behaviour for suspicious activity and deviations from normal patterns, rather than simply relying on known signatures. This helps to detect previously unseen threats such as zero-day exploits.
• Response automation: EDR platforms can help to automatically respond to security incidents, helping to minimise the impact of an attack. This can include automated blocking of malicious processes and completely isolating a device from the rest of the network to limit lateral movement.
• Additional features: In addition to anti-malware, many EDR solutions provide additional functionality to protect endpoints from a variety of threats. This can include content control, external device blocking, patch management and much more.

Having some form of endpoint protection solution in place is a necessity for any organisation to help protect against common cyber threats.

What is a SIEM solution?

SIEM is a centralised platform designed to collect, analyse, and interpret data from various sources across an organisation's IT infrastructure. By aggregating logs and events from networks, applications, systems, and devices, SIEM enables security teams to detect, investigate, and respond to potential threats in real-time.

How does SIEM work?

SIEM solutions correlate security telemetry from lots of different sources to identify patterns that could indicate malicious activity. Security analysts can use a SIEM solution to maintain visibility over an environment, detect threats, and investigate security events using log data.

SIEM plays a pivotal role in enhancing cyber resilience by enabling:

• Threat detection: By continuously monitoring network traffic and system logs, a SIEM solution detects anomalies and suspicious activities that could be an indicator of attack (IoA) or indicator of compromise (IoC).
• Incident response: SIEM streamlines incident response workflows by providing contextual information from log data, which helps to speed up the investigation and remediation of security events.
• Compliance management: SIEM helps organisations comply with regulations and standards such as ISO 27001 and PCI DSS by providing audit trails, log retention, and reporting capabilities.

SIEM solutions usually rely on pre-determined detection rules to help identify threats across a network. If a threat is detected, a SIEM platform will automatically alert you to the security event, provide a detailed overview of the incident and step-by-step remediation advice to help you fix the issue. A SIEM solution will also append any relevant security logs to the incident to help with investigation and reporting.

How do EDR and SIEM work together?

To put this all into context, let’s use a quick analogy.

Using SIEM to monitor logs is comparable to having CCTV watching your building. It can notify you if it detects movement, it might be able to identify particular people or animals, and it records all the footage in case you need to review it later. Having an EDR solution is like a lock on your front door, it works to simply secure the main point of entry.

If you only monitor EDR or endpoint logs, it’s like having a single CCTV camera pointed at your front door. An attacker could simply find another point of entry, as we know modern cyber threats extend beyond the endpoints. So, it’s important to monitor logs from all areas of your organisation.

That’s where SIEM comes in. It can monitor logs from many other areas of your environment, correlating them into a single solution to help you detect threats. A SIEM solution can also utilise an EDR platform as a log source, helping to detect threats that are affecting individual endpoint devices.

Where does XDR fit in?

OK, so you have the basics on EDR and SIEM and you’re ready for another acronym. Here’s a quick recap with the added bonus acronym of XDR, too.