When a web server (like Apache or Nginx) is misconfigured, it may not have a default index.html file. When a user navigates to a directory without an index file, the server may display an "Index of /" page — a simple, clickable list of all files in that directory.
In 2021, a fake “updated wallet.dat” circulated on hacker forums. Users who downloaded it lost access to their own existing Bitcoin wallets because the malware exfiltrated their actual wallet files. indexofbitcoinwalletdat updated