Hp Pavilion Dv4 Laptop / CPU 100% Ram Around 50%?

I'm running just a standard Hp pavilion dv4 laptop, windows 7 64 bit and i5 core.Two days ago my computer started running at 100% or spiking between random % and 100% on idle, or when I run just one program ( it does it with word, firefox and other small programs).I opened up the task manager and checked to see if there were any background services running that were causing this, to my knowledge there aren't any. The spikes are happening when any program is ran, thus making my laptop extremely slow. It also has a few moments when it has shutdown to avoid overheating.

A list of things I've done so far to try and find/correct this problem are:Disabled all startup programs and services, gone to safe mode, used malwarebytes,spybot and AVG to detect if there was a trojan or virus causing this severe problem. A few anomalies I've discovered that lead me to believe it might be a virus were: Windows defender will not open and is currently off, same with windows security center. When I search google on firefox for specifics such as "cpu 100% or overheating and such" I'm redirected to msdb or some microsoft support website, without it bringing up the google results. It's also done this in general when i try to search any other random sites on google.It's either a very clever trojan or worm or a hardware failure.I contacted HP told them what was up. They just opted for me to send it in and have them replace the CPU and motherboard for 320$ which is kind of ridiculous without them even taking a look at it. When this problem initially occurred and I checked what processes were running at the time, there was one SVChost.exe file that was tagged as "bit-coin miner". I stopped it, but yet, I know that some people are out there hijacking other GPU with bots to mine for bitcoins. That made me thing that it could be a virus and not a hardware problem.