Windows 10: Why did Windows Defenders fail to stop the threats from running?

I have already used Win10XPE to remove the threats shown in the attached screenshot. I just want to know why Windows Defender failed to stop the active threats from running on my device. When I clicked on "Action"-->"Remove", nothing happened, so I had to use Win10XPE, which allowed me to remove them.

:)

 

Windows defender: "Threat service has stopped"

Hi,

For us to better assist you, we need to ask a few questions:

• Which version of Windows are you using?
• Were there any changes made before experiencing this issue?

For steps to help resolve the issue, you can refer to
cuda18's post on this
link.

Looking forward to your reply.

Thank you.

 

Windows defender false positive - forced to allow threat

Windows defender has started to identify C:\Windows\System32\mshta.exe as a threat [normally reported as a Trojan Powessere.G]. I use mshta.exe to run an hta custom MsgBox - I have been hoping to keep using my current CustomMsgBox tool [batch file calling a vbs-hta file] until later this year when I hope to have had enough time to replace it with a PowerShell alternative.

Windows defender's notification lets me "allow the threat" but that seems to me to be a bigger security hole than is necessary - it will now ignore a potentially real intrusion when all I want to run is a genuine Windows component. My immediate problem is fixed but I would prefer to fix the false positive using the exclusions list.

I cleared the 'Allowed threats history' so I could use the exclusions list instead. I added C:\Windows\System32\mshta.exe to the file exclusions list and I checked that it had taken properly by checking the exclusions list both in the UI & in the Registry. But the exclusion made no difference, it continued to detect and block the exe.

I have repeated the attempt several times [by clearing the allowed threats list & exclusions list beforehand] and the results are the same every time
- allowing the threat works,
- using the exclusions list has no effect.

I studied the relevant tutorial but have not spotted an error in what I have been doing - Add or Remove Windows Defender Exclusions

Does anybody with experience of using the exclusions list to counter false positives have any suggestions for me?

Denis

 

Windows defender: "Threat service has stopped"

Some users might be experiencing a glitch with starting the Threat Service (Windows Defender Antimalware Service) that was apparently delivered on Patch Tuesday. The first thing to try would be manually restarting the PC lots of times, with a break
between the restarts (Start button > Power > Restart), as described by Le Boule in this thread:

Windows Defender - Virus & Threat Protection - Restart Now

This issue might also be related to the known glitch where the Security Center Service needs to be restarted in order to get Windows Defender up and running – so try this:

• Manually restart the Security Center, and then attempt to start the Windows Defender Antivirus Service:

1. Press Win Key + R

2. Type “services.msc” and click OK.

3. Right-click on Security Center and click
Restart

3. Right-click on the Windows Defender Antivirus Service and click
Start.

If that doesn't work, then you should follow these general troubleshooting steps:

• Remove any undetected malware by scanning with several third-party malware-removal apps, starting with Malwarebytes Free:

List of Malware Removal Tools

• Run the cleanup tools for any previously installed or preinstalled AV apps:

List of anti-malware product removal tools

• Run the standard Windows 10 system integrity checks:

System file check (SFC) Scan and Repair System Files & DISM to fix things SFC cannot

Source thread:

Defender stopped and cannot restart it

If the above steps fail to start the Windows Defender Antivirus Service, then you can try the steps provided here:

Problems starting Windows Defender in Windows 8/8.1/10

I hadn’t noticed that

PrashantKumar96 actually advised setting DisableAntiSpyware = 0
in this forum article. Before you do that, you should always try just deleting any possible entry for
DisableAntiSpyware = 1, since that setting might have been added by another program or by malware – and that setting will always prevent Windows Defender from starting. For the sake of both ease and safety, this should be done with a REG command.

Type “cmd” in the search box; and then right-click on
Command Prompt and select Run as administrator.

And then copy, paste, and enter this command:

REG DELETE "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware

This is the proper way to enable Windows Defender when it's been turned off via Group Policy.

We can see that there’s a general confusion with respect to this Group Policy setting by the way that Brink equivocates deleting the
DisableAntiSpyware entry with setting its value to 0.

DisableAntiSpyware DWORD

(delete) or 0 = On

1 = Off

Turn On or Off Windows Defender Antivirus in Windows 10

But this setting actually uses a three-state logic, where the absence of the setting specifies the normal
Automatic Disabled compatibility mode for Windows Defender.
Setting DisableAntiSpyware = 0 sets Windows Defender's operational state to “always on” [DisableAntiSpyware = 0 (logical “no/never”)], whereas [DisableAntiSpyware = 1 (logical “yes/always”)] sets Defender’s
operational state to “always off”; and where removing the DisableAntispyware registry entry simply returns Defender to its default operational state – where Defender will be automatically disabled by the installation of any third-party AV app, and
automatically enabled when a third-party AV app is uninstalled.

As the "method of last resort", you can set the Group Policy for Windows Defender to its “always on” mode:

Type “cmd” in the search box; and then right-click on Command Prompt and select
Run as administrator.

And then copy, paste, and enter this command:

REG ADD "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /d 0 /f

Then click the Restart button (it might be necessary to restart the PC first).

If this doesn’t work, then you should remove this setting with the REG DELETE command provided above.
Note that this REG ADD command is just the safe and easy way to perform the registry edit that was described in the answer to this thread:

https://answers.microsoft.com/en-us...-stopped/5724ac44-80ff-4a2f-a3a5-46686a92edd9

No internet-connected PC is safe when it's running without real-time protection. So if you’re not able to restart the Windows Defender Antivirus Service, then the best course of action would be to just temporarily install a free third-party AV solution
until we can get a handle on things. Replacing Defender with a third-party AV app should at least provide you with a viable alternative for Defender’s real-time protection, and thus let you safely connect to the internet:

https://www.pcmag.com/article2/0,2817,2388652,00.asp