By default, older versions of Bitcoin Core did not encrypt these files, meaning the private keys were stored in plain text. The Danger of "Index Of" Leaks
If an unencrypted wallet.dat file is indexed by a search engine: How to Find and Recover Lost Bitcoin Wallets - Ledger indexofbitcoinwalletdat exclusive
At the core of the Bitcoin Core client is the wallet.dat file. This file is a BerkeleyDB database that functions as the brain of your Bitcoin wallet. It does not "contain" your actual Bitcoins—which exist on the public blockchain—but rather the required to spend them. By default, older versions of Bitcoin Core did
These are the unique strings of characters that prove ownership. indexofbitcoinwalletdat exclusive