I have noticed over the last month that my off peak data has been used at a rate of approx 350MB per hour - this has meant that I have gone over my quota and slowed down by my ISP to 256k. There is no one in the house using it (2am-8am is my ISPs off peak hours) at that time. My PC and other wireless devices (ipad and iphone) are turned off. I have changed the wireless password on my modem 3 times and it is now 30 digits long. So I don't think someone else is using my wireless access between 2-8am. It has been suggested by my ISP that I may have malware/spyware on my computer. Sorry for my ignorance, but can malware still run if the PC is off? I did look at my modem's log and followed an IP address to a service called Amazon Simple server Storage. Could this company possibly be the culprit? I am not too tech savvy, so any assistance appreciated. I have run a barrage of spyware cleaning software eg malware bytes; spy bot etc....

Cheers Val