I know we have done this tip before, but I hear it just happened to your sister. When you get a pop-up on your computer and you are to call support to help to get it fixed. Nothing good can happen from this.
How many times do we need to tell you. Don't give them any CC, Bank, phone number to call. Don't call them. And whatever you Do, DO NOT allow them to connect, NO MATTER WHAT!!!!!
If they connect. They can download everything. This often happens visiting even benign web sites. The site has been hacked and when you visit it, up pops this message.
Actually at this point you likely don't have a virus, just the text message from the hacked site. I WILL REPEAT. DO NOT CALL THEM. Simply restart your computer. Then do a full scan using the anti-virus software you have. If you don't have antivirus software at least go to Malwarebytes.com and download their free software and run a scan.
If you let them access your computer get help from a known technical support company. The bad people probably have installed a key capture program and will spy on you. If they got your CC or bank information contact your bank, CC company and we suggest doing a credit stop.
LISTEN TO US. YES WE ARE YELLING!!!!!!!!