What a Microsoft Defender alert means and what to do

Every managed Windows computer is protected by Microsoft Defender, the security software built into Windows. We manage its settings through NetLock RMM, so it stays switched on, keeps its definitions current and runs regular scans. When it finds something, both you and we are told.

The usual message: threat blocked

The most common notice says a threat was found and has been quarantined or removed. That means Defender did its job: it stopped a harmful file before it could run, often a download or an email attachment. You do not need to do anything, and you should not try to restore the file. We see the same alert in our console and check whether anything else needs attention. If you are worried, or you recognize the file as something you were expecting from a colleague or supplier, tell us and we will look into it.

Messages that need action

Contact us straight away if Defender says a threat could not be removed, if it asks you to restart to finish a clean-up, or if it reports that protection is turned off. Also contact us if you see repeated alerts for the same thing. These can mean something keeps coming back, for example from a USB stick or a synced folder.

Fake security warnings

Real Defender notices come from the Windows notification area and the Windows Security app. They never show a phone number, never ask for payment and never tell you to install anything. A browser page that flashes red, plays a warning sound and tells you to call "Microsoft support" is a scam. Close the browser (on Windows, press Ctrl + Shift + Esc, select the browser and choose End task if it will not close), do not call the number, and let us know.

Please do not turn it off

Occasionally a program or website asks you to disable your antivirus to install something. Do not do it. If a piece of software you need is being blocked, email hello@bitnode.tech with its name and where it came from. We will check it and, if it is safe, allow it properly without lowering protection for the whole computer.

Macs

Macs include their own built-in protections, and the same rules apply: never act on a pop-up that asks you to call a number or pay, and tell us about anything unexpected.