Searching for open directories containing wallet files is a common tactic for hackers. However, it is a double-edged sword:
Using Google dorks:
intitle:"index of" "wallet.dat" inurl:wallet.dat Index-of-wallet-dat
In web hosting, if a folder (directory) on a server does not contain an index file (like index.html Searching for open directories containing wallet files is
: A small e-commerce site running Bitcoin payments had a /backup/ folder with directory listing ON. Inside was wallet.dat (unencrypted) containing 12.5 BTC (~$350k at the time). Index-of-wallet-dat