Email claiming hack. Wants bit coin

I was just deleting my junk mail file today and discovered an email saying a colbalt virus had been put on my system. Says they have all my info and will share. Says they want bit coin. I think this is fake. I deleted it. That said I think I will have my MAC reviewed / checked for virus. I just add here because I looked on line for info and the info here was good but says it has been a while since anyone added something. So I present my two cents.