Unusual Pop up reporting Hacking

I'm sending this to get feed back on potential issues. This is my mother's (86) computer an HP Desktop running Windows 7 and webroot security for antivirus and firewall.

She was experiencing issues with her printer and the computer indicated it was no connected. While trying to reinstall the printer, she got a popup window that said she had been hacked. The popup header was from Witheasemarketing.com.

The popup contained the message and a phone number to call Geek Tech. She called it and apparently spent several hours on the phone with the tech support. In the end, he told her she had 9 hackers using her computer and she should shut down her computer since she didn't have any anti-hacker protection. He sent her an text message offering several options ranging in price for 100 to 500 dollars.

She refused to purchase anything without talking to my sister who called me.

I ran a search for witheasemarketing and it appears to be a legitimate social media marketing firm with no computer protection services so I don't know why it came up.

I ran the phone number she called and it did, in fact, return a Geek Tech, LLC and it reports being a third party computer repair company.

I don't like that my mom called a number that popped up on the computer screen. She does subscribe to a Fastfix123.com (not sure of the URL). But don't understand the pop up.

My sister is calling the company to see what was going on and I was hoping you could help a bit.

I'd like to know about anti-hacker software since I've been under the impression that antivirus and firewalls were the protection needed.

Would a company have a third party service providing popup notices of hackers? That is so weird. :confused