Hello everyone!

More than a Week  ago my single btc from offline paper wallet was stolen

it was created in 12.2018 and never used since that time

I am totally frustrated not only because of loss but also becasue i cant get what do i did wrong!

Also i want to mention that the adress it was moved on, is still untouched and have got just a single transaction(my btc)

u can supervise it here

https://www.blockchain.com/btc/address/1CtmmUkxEbQ8nsa2XFSKy7bo5XmBxYFP5n

what can it be?why it is still untouched? why it happened just in 6 month?