and at the time thats what i did, i ran every single scanner and anti-malware software (the ones i trust anyway) and there was nothing there. in my case it was a mystery, that will never be solved. unless someone at blizzard, (who knows maybe a GM) who would have access to let someone into your account did. but thats just stupid speculation.I do suggest scanning your computer with Malwarebytes or some other anti-malware program . Best of luck to you.