You bought the HDD or it belongs to someone? What you bought suppose not to have non deleted files. But if it has files that are not yet deleted, why do you want to steal someone's wallet.
You can not have access to the wallet with the pubkey. No bitcoin private key that is long up to 90 characters.
If it is not your wallet, you do not need to make any effort to recover the wallet. You said you bought the HDD. If this is not a made up story, it is better you avoid malware.
Indeed i buy old HDDsevery saturday in the yard market for God knows since,when. Ihave houndreds of them in my garage. And i buy them for only one reason - in search of old abandoned wallets. Once i was lucky to find a wallet with 3 BTC back in time when it cost €3000/BTC, so all of my spendings (old HDDs cost not more than €5/pc), paied back. That is why i continue this "hobby". So now I've stumbled upon something that is not a wallet.dat and i can not figure out how to open it.