Judging by the fact that these two wallets hold a ton of money i think it is safe to assume that your computer is likely to be infected with malware as DannyHamilton said. Do NOT send any bitcoin or altcoin to wallets that you currently have on your computer, or your money may be gone.

Either factory reset your computer or install a good antivirus program to clean out the viruses, before you do anything else. As for the transactions, unfortunately they have confirmed and therefore is irreversible.