Not much. Just forget about the wallet and use a new one.
I too in past have lost my wallet with 4 digit sums to a hacker. Not sure how they got hold of it but there could be two reasons I could think of where I was not cautious.
Once I opened my wallet in a pirated version of Windows. Pirated software are known to have clipboard watcher and keyloggers. And the likelihood of getting a spyware are also greater in Pirated software.
Another mistake of mine was to store my private key in google drive. Many app we use do ask to read and modify our drive data. They might theoretically get hold of our wallet.