Possible Ransomware/Virus Attack- can't find IP address (plus a non-functional router!)

[teraman9]

My relative's PC has been acting weird for about 5 days, with a mysterious installation of "SlimCleaner" installed. As far as we know nobody ever installed this. The program would randomly offer a "virus scan," which we never clicked on in fear of a virus activating. BUT, either somebody accidentally clicked it (which SHOULDN't activate a virus considering this software had a decent reputation), or something else we don't know about trigger it. However, after restoring settings from April 9th, you can't even GET INTO the PC, requesting an IP address and password to sign in. However, it boggles my mind that a hacker would need an IP address for one to "sign in" if they already managed to get the virus/possible ransomeware on there. Any suggestions on what this is?

Oh, and not to mention, THE ENTIRE WIFI ROUTER ISN"T WORKING. As in no other devices can connect. Will i have to replace the router and find a way to restore the computer?

PC SPECS:
Windows 7 Home Premium 64-bit
Custom Built PC with an AMD A6 series CPU (I don't remember which one exactly) and 8 GB of ram

NOTE: I haven't had a chance to actuallly take a look for myself at the PC, but my relative knew enough for me to identify the current dilemma. I will update this when i get a chance to go over to his house later today, so if i don't have enough specific information then I will provide more later anyways.

TL;DR? My tech-dumb relative's PC has been acting strange, a virus might have accidentally triggered, my PC won't sign on without an IP address/password (neither of which i know ATM), and the entire wifi router isn't working.

 

[ffg7]

the wired part of the router cannot access the net either? what anti-virus\malware programs does the relative have?