Yes, but what I don't understand, would it be, what does the hacker gain from this? this wallet when you download to your computer, try to mine, try to steal your bitcoins that are in another wallet?
How did you know that the wallet is trying to mine from your computer?
The software/wallet you installed in your PC might be a malware or a keylogger that could steal other wallets if they found that you have another wallet with balances.
Much better if you still have balances from other wallets use other devices to recover them and transfer them to a new wallet installed on different PC which is known clean.
For now, there's no way to recover the 15BTC if it is already confirmed the only thing that we can do now is to switch to a well-known wallet which is known safe.