you might have accidently clicked on an email that lead to a fake sign-in site or something. Either that, or it was just someone who was testing their skills.
Either way, hope it doesn't happen again!
After this hack, my pc detected 2 trojans, and the directory of the trojans led to a file called Web.dat in a Chrome folder, I opened it in text format, and it had everything, my adress, my phone, my passwords...
Either way, hope it doesn't happen again!