This is my first time here and after seeing the site I've realized that I'm in the right crowd to seek help about my problem. couple of weeks a go I received an email saying that the person knows my password (I'm not sure where I used that password, but it looked like something I would have used some time) and he (because after around a week later the email the person called me on my phone number and wanted to talk to me) asked me to pay him money, $1800.

I know your password is: 32413241jobs
You got infected with my malware, RAT (Remote Administration Tool), while browsing the web where my iframe was placed, in the background you got redirected to my exploitpack, your browser wasn't patched so you got infected!
My malware gave me full control over your computer and access to all your accounts (see password above)!
I COLLECTED ALL YOUR PRIVATE DATA!
YOU KNOW WHAT I MEAN - I KNOW ALL YOUR SECRETS - YOU KNOW THAT THIS ISN'T A JOKE!
After that I removed my malware, to not leave any traces.
If you don't pay me exactly 1800$ in bitcoin (BTC), I will PUBLISH ALL YOUR DATA, send it to all your contacts, over email, post in on social network!
WE BOTH KNOW - this is a very good price - compared to LIVING HELL!
YOU GOT 2 DAYS TIME TO GET THE BITCOIN (BTC) AND PAY!
One exchanger is www.paxful.com (there are many ways to buy bitcoin), other is www.coinbase.com
You also can Google for other sites, "Where to buy bitcoin?"
My bitcoin wallet is: 1GmebPccNzPrkFiWknizbsCfzgXv27JGZP
Copy and paste my wallet, it's (cAsE-sensetive)
After receiving the payment, I will delete all your data and you can life your live in peace like before.
If you get this email multiple times, it's to make sure you read it.
You will make everything worse, if you show this email to anyone - this should stay our little secret!
MailClientID: 7126891076
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Now I wonder how I can make sure that there is no such virus, called RAT on my computer or if there is one, PLEASE help me clean my computer from this thing.
THANK you very much in advance! Thanks for being there for us in need!
Peace