SIEM, in one sentence
A Security Information and Event Management (SIEM) platform collects logs and events from across your servers, endpoints, firewalls, and applications, and correlates them in one place so a pattern that's invisible in any single log becomes obvious when you see it across all of them together.
A concrete example of why correlation matters
One failed login on one server means nothing — someone fat-fingered a password. But 40 failed logins across 6 different servers from the same external IP, within 3 minutes, followed by one successful login on the 7th attempt — that's a brute-force attack that succeeded, and it's only visible as a pattern, not as any individual log line. Without a SIEM, that pattern is sitting across seven separate log files that nobody is correlating. With one, it's an alert that fires the moment the pattern starts.
What a SIEM actually does, mechanically
- Collects — agents or log forwarders ship events from every system into a central store
- Normalises — different systems log differently; a SIEM translates them into a common format
- Correlates — rules and detection logic flag patterns across systems, not just within one
- Alerts — the moment a correlation rule fires, someone (or something) gets notified
- Retains — logs are kept centrally, which matters for both investigation and compliance (see our POPIA checklist for why centralised, tamper-resistant logs matter there too)
Do you actually need one yet? An honest framework
Signs you probably do
- You have more than a handful of internet-facing systems
- You're subject to a compliance framework that expects security monitoring (POPIA's "appropriate technical measures" language leans this way for higher-risk processing)
- You've had a security incident before, or near-miss, and currently have no way to reconstruct exactly what happened
- You run a SOC, IT security team, or outsourced security function that needs a single pane of glass
Signs it might be premature
- You're a 3-person business with one server and no internet-facing services
- Nobody on your team (internal or outsourced) has the bandwidth to actually respond to alerts — a SIEM nobody monitors is just an expensive log archive
The honest answer for most growing SA SMBs is: not yet at 5 employees, almost certainly yes by 30–50, and the inflection point depends heavily on what data you hold and how exposed your systems are — not purely on headcount.
Why we use Wazuh specifically
Wazuh is open source, which matters for two practical reasons beyond cost: there's no per-agent licensing fee that scales painfully as you grow, and the detection ruleset is transparent and auditable rather than a vendor black box. It also covers file integrity monitoring and vulnerability detection alongside log correlation, which means one platform does double duty as both a SIEM and a baseline security monitoring tool.
Not sure if you're at the SIEM-ready stage?
We'll give you a straight answer based on your actual risk profile, not a sales pitch either way.
