As we mentioned in previous publication Microsoft has removed the ability to disable Microsoft Defender from the Registry Windows 10.
From Windows Vista, users could completely disable Microsoft Defender and possibly any other security software by using the "Turn off Microsoft Defender Antivirus" in the group policy settings.
When the policy is enabled, a “DisableAntiSpyware” registry value is created and set to 1 under the HKEY_LOCAL_MACHINE \ SOFTWARE \ Policies \ Microsoft \ Windows Defender key, as shown below.
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE \ SOFTWARE \ Policies \ Microsoft \ Windows Defender] "DisableAntiSpyware" = dword: 00000001
Once activated this key will disable “Microsoft Defender Antivirus, as well as software and third-party antivirus applications”.
At documentation of DisableAntiSpyware, Microsoft states that the DisableAntiSpyware value will be ignored and will no longer be used to disable antivirus software.
Microsoft also states that if a user removes the installed antivirus solution, Windows Defender will automatically activate to protect him / her.
"Consumers may choose to run another AV solution, but if for any reason the application is disabled, Microsoft Defender AV will be reactivated to ensure that there is no user protection gap. ”
Why
Just as Windows administrators know about group policy settings in DisableAntiSpyware, so do malware developers.
Many malicious programs (TrickBot, Novter, Clop Ransomware, Ragnarok Ransomware, and AVCrypt Ransomware) have abused this policy to try to disable antivirus protection on Windows.
With the release of Windows 10 1903, Microsoft added a new feature called Tamper protection which prevents her change των ρυθμίσεων του Windows Security and Microsoft Defender from programs, Windows command-line tools, registry changes, or group policy changes.
So if a piece of malware added the DisableAntiSpyware value to the Registry and then rebooted the computer, upon reboot, the Tamper Protection will remove the value.
So now that Microsoft Defender is completely ignoring the value of DisableAntiSpyware, Windows 10 users have much greater protection against threats trying to disable security software using this technique.
