SIEM
A SIEM collects, normalises and stores logs and security events from across an IT estate, then provides search, correlation and reporting capabilities. It is the long-term memory of a security operations team and the backbone of many compliance requirements.
What a SIEM is
A SIEM ingests logs from operating systems, applications, network devices, identity providers, cloud services and security products. It normalises them into a common schema and stores them for a period defined by the organisation’s compliance and forensic needs (often 6 months to 3 years).
On top of that, a SIEM provides:
- search across all stored events;
- correlation rules that fire alerts when patterns appear (e.g. multiple failed logins followed by a successful one from a new country);
- reporting for auditors and regulators.
SIEM vs XDR vs EDR
An EDR is deep and narrow on endpoints. An XDR is deep across security data sources (endpoints, cloud, identity, network). A SIEM is broad — it ingests everything, including non-security data — but shallower on detection out of the box.
A SIEM alone produces a lot of noise. Most mature organisations layer them: XDR for operational detection, SIEM for retention and ad-hoc searches, both feeding the same SOC.
SIEM at Hexceos
Our SOC can operate on top of your existing SIEM (Splunk, Microsoft Sentinel, Elastic, Datadog) or use our internal stack. The choice depends on the compliance scope and the maturity of your existing tooling.
Last updated: 19 May 2026