Popup says Windows Defender has detected a trojan and locks PC

[bjedrick]

Earlier this year I got a popup screen which totally locked up my laptop PC.  It said that Windows Defender had detected a trojan, my PC was compromized, and not to turn it off but to call Microsoft Support at the displayed number.  I did, and it turned out it was not Microsoft Support, but a company called Capital Network Systems, which said it was a network problem and persuaded me to pay to have them remove it. However, the other PC on my network was not affected.

I eventually got them to refund my money. but then had to pay a hefty calcellation fee to do this.  They keep calling and emailing although I keep telling them to stop.

Recently I got the popup again, but this time just shut down the PC, then when I powered it back on it just looped and would not come back up.  Tried this several times then got a wiindow which first said Automatic Repair Started, then Repairing disk errors - this may take an hour. I let that run, and eventually the PC came up and everything was fine.

I have Windows 10 with a Firefox browser and McAfee Protection, so I do not even use Windows defender.  This happens unpredictably so I can't recreate it, but at least now can avoid it by shutting off the PC, but want to alert other users if they get this.

However, why didn't McAfee prevent this from happening in the first place?  

[Sudharsanam_G1 · Accepted solution]

Hi @bjedrick 

We regret for the inconvenience!

This seems to be an unwanted browser extension/software causing the trouble. McAfee Malware Cleaner (MMC) is a free tool that cleans malware, adware, viruses, and other threats from your Windows computer. kindly refer the below article for troubleshooting steps.

McAfee Malware Cleaner

Alternatively, You can always contact the chat support using below link for immediate assistance.

McAfee Support

Regards,
Sudharsanam G

[bjedrick · Accepted solution]

Downloaded and ran the malware cleaner. It said it cleared 2 infected files and the PC restarted correctly.  It would be great if this could be periodically scheduled like a scan.

Now will have to wait and hope I don't need it again.  Thanks.

[nualbewitched]

In the end, I was successful in obtaining a refund. nonetheless, this came with a substantial cancellation cost. I've asked them to stop phoning and emailing several times yet they continue to ignore me.

dordle