“We've got antivirus on everything” is one of the most common things we hear when we ask a new client about their security setup. It's also one of the most common false assurances in IT, not because antivirus is worthless, but because it's solving a much narrower problem than most business owners assume.
What traditional antivirus actually does
Signature-based antivirus compares files against a known list of malicious code. It's reactive by design: something has to be identified as malware, somewhere, before your software recognises it as malware. Modern attacks are built specifically to get around this: living-off-the-land techniques that use legitimate system tools, malware that mutates itself, and credential-based attacks that never touch a “file” in the traditional sense at all. None of that trips a signature match.
What XDR (Extended Detection and Response) does differently
XDR doesn't just look for known-bad files. It watches behaviour across endpoints, identity, email, and network activity together, and correlates it. An account signing in from an unusual location, then a process spawning something it's never spawned before, then an attempt to disable logging: individually those might look unremarkable. Together, they're a textbook attack chain, and that's exactly the pattern XDR is built to catch.
Why the "24/7 monitored" part matters as much as the tooling
A detection platform that fires an alert nobody looks at until Monday morning is not meaningfully different from having no detection at all. Attackers don't work office hours, and the gap between initial access and real damage, whether that's data exfiltration, ransomware deployment, or wire fraud, is frequently measured in hours, not days. This is the actual argument for managed detection and response (MDR): a real person, watching in real time, able to isolate a compromised device or revoke a credential the moment something is confirmed malicious, at 3am on a Sunday exactly as reliably as 3pm on a Tuesday.
What this looks like in practice
Our own Managed Cyber Security service runs on Adlumin, an AI-driven XDR/MDR platform, with our SOC team monitoring it around the clock. Not as a replacement for good IT hygiene (patching, MFA, backups all still matter), but as the layer that catches what those measures miss, and does something about it before it becomes a headline.