Strange virus like behavior

[pathogen]

Tuesday I noticed my phone battery had died in an hour and was ridiculously hot. It had been running extremely slow. I noticed the internal memory kept changing after a reset. It would start out with 80mb free and within a few minutes had dropped all the way down to 6mb. I soft reset and thought it was a fluke but after recharging the phone the same thing happened again. I hard reset the phone and loaded only select applications. So far the same problem has not occurred again.

The most interesting thing is that I noticed my data usage DOUBLED in two days. I had 400megabytes of usage and today I noticed it was at 800 megabytes. Almost as if my phone was being used to distribute something. I did buy the phone used on ebay last month and hard reset before I used the phone.

I have a backup image saved if anyone is interested. I did not download anything out of the ordinary however.