On some Windows 10 and 11 computers, Microsoft Defender Antivirus may repeatedly warn about the same threat, although you’ve taken the necessary action (remediated) on that threat.
When you click “Start actions” after choosing “Remove”, nothing happens. Windows Defender would keep showing that non-existent threat.Read more
Since July last week, Windows Defender started issuing Win32/HostsFileHijack “potentially unwanted behavior” alerts if you had blocked Microsoft’s Telemetry servers using the HOSTS file.
Out of the SettingsModifier:Win32/HostsFileHijack cases reported online, the earliest one was reported at the Microsoft Answers forums where the user stated:
I’m getting a serious “potentially unwanted” message. I have the current Windows 10 2004 (1904.388) and only Defender as permanent protection.
How is that to evaluate, since nothing has changed at my hosts, I know that. Or is this a false positive message? A second check with AdwCleaner or Malwarebytes or SUPERAntiSpyware shows no infection.
After inspecting the HOSTS file from that system, it was observed that the user had added Microsoft Telemetry servers to the HOSTS file and routed it to 0.0.0.0 (known as “null-routing”) to block those addresses. Here is the list of telemetry addresses null-routed by that user.Read more
When you try to save a file on the desktop or the documents folder on your Windows 10 computer, it may show the “File not found” error message. Here is the full error message verbatim:
.. with the “Unauthorized changes blocked” error in the Notification area and the Action Center.
For each error, an action center notification along with an event log entry is created.
The Windows 10 action center may show a prompt with a black exclamation inside a yellow triangle icon in the Notification area. When you click on that, it opens Windows Defender Security Center. In the Windows Defender Security Center, underneath the “Virus & threat protection” icon the exclamation mark inside a yellow triangle shows up again, with the note reading “Set up OneDrive for file recovery options in case of a ransomware attack.”
The Windows Defender warning shows up even though OneDrive is already be configured, syncing and working perfectly fine. Also, clicking the “Dismiss” link beneath the warning message may do nothing.
If OneDrive is already setup correctly and working fine, then the yellow exclamation warning can be safely ignored. But if you’re desperate to stop Windows Defender from issuing the false alert, this post tells you how to do so.Read more
The “Security and Maintenance” Control Panel applet or the Action Center in Windows 10 may warn you that Windows Defender is disabled and no anti-virus is protecting your system. If you open the Windows Defender interface, it offers to Turn On protection, but the button doesn’t work.Read more
After installing Malwarebytes Premium 14-day trial or licensed product, your anti-virus software (e.g., Microsoft Defender Antivirus) may get disabled automatically. In this scenario, when you attempt to start the Microsoft Defender Antivirus Service (WinDefend) via the Services console, it shows the following error, and the service wouldn’t start.Read more
When you attempt to update Windows Defender via Windows Update, error 0x80070643 may appear, and the definition updates fail to install. Here is the full error message:Read more
After upgrading to Windows 10 version 1709 (Fall Creators Update), when you open Windows Defender classic interface MSASCui.exe, and click View details on the History tab, the following error message appears:Read more
When you try to run files downloaded from the internet, the following error may appear on your Windows 10 computer:
In some systems, the same error may pop up also when opening Command Prompt or PowerShell.Read more
Windows 10 and 11 include a beneficial security feature named Controlled folder access, which is part of the Microsoft Defender Exploit Guard. You may have noticed the Unauthorized changes blocked notifications. Microsoft Defender’s Controlled folder access feature is the one behind those notifications. Controlled folder access helps you protect valuable data from malicious programs, such as ransomware.
This article explains how to configure CFA and prevent Unauthorized changes blocked notifications when running a program.
