Switched from AlienVault to Wazuh. Saved $60k, detection gap is minimal for our size.

So the collective wisdom seems to be that moving from a proper, polished SIEM to a free, open-source alternative is a one-way ticket to detection oblivion, or at least a full-time job for three engineers just to keep the logs flowing. Having just completed a rather heretical migration from AlienVault USM (now AT&T Cybersecurity, or whatever it’s called this week) to Wazuh, I feel compelled to toss a slightly damp blanket on that particular fire.

Let’s start with the sacred cow: the detection gap. For a mid-sized enterprise like ours, the notion that we’d be instantly overrun by undetected threats the moment we switched off the commercial product was, frankly, overblown. The core rulesets for things like brute force attacks, suspicious process execution, and common web attack patterns are remarkably comparable. Wazuh’s integration with the MITRE ATT&CK framework is no afterthought. Sure, you lose some of the glossy, pre-packaged “threat intelligence” feeds that mostly just generate noise about malware that hasn’t been seen in the wild since 2015. But in practice, our SOC team’s alert console didn’t suddenly go dark. It got quieter, in a good way. We’re now alerting on behaviors we actually care about, not just because a vendor’s threat research team needed to justify their quarterly headline.

Now, the $60,000 savings. That’s not just license fees, though that’s the bulk of it. It’s the death of the perpetual “premium support” contract that required a three-day escalation process to get a meaningful answer, and the end of paying per GB for ingestion of our own internal telemetry. The real cost was always in the operational model: being held hostage by a vendor’s idea of what data is “valuable” enough to warrant storage. With Wazuh, the data lives where we want it, indexed how we want it. The initial setup labor was not trivial—let’s not romanticize the open-source grind—but it’s a one-time capital expenditure of effort versus a recurring, ever-increasing operational tax.

The most sardonic part of this whole experiment? Our contract benchmarking against peers showed we were paying nearly 40% more than some for AlienVault, simply because we’d signed our last renewal during a “security crisis” and lacked the leverage to push back. Moving to Wazuh wasn’t just a technical decision; it was the ultimate negotiation tactic. You can’t argue with zero. The vendor’s inevitable “But what about the risk?!” scare-mongering during our exit interview fell completely flat when we presented our own comparison metrics showing equivalent coverage for 90% of our use cases.

I’m sure the purists will arrive shortly to lecture me on advanced threat analytics, machine learning models, and SOAR playbook depth. And for a global bank, those points might hold water. But for the rest of us, operating in the real world of constrained budgets and skeptical CFOs, the calculus is shifting. The question is no longer “Can an open-source SIEM work?” but “At what point does the premium for a commercial product stop being for security and start being for comfort?”

—Bella