By default, some web servers (like older versions of Apache) will display a list of all files in a directory if a default "index" file (like index.html or index.php ) is missing. If a developer or administrator leaves a file named password.txt or passwords.csv in such a folder, anyone with a search engine can find and read it.
A failure to properly protect sensitive files with a .htaccess rule can leave them public. Risks of Exposed Password Files index of passwordtxt link
When such a file is exposed via an indexable directory, anyone who finds the can download it instantly. Automated bots constantly scan for these patterns, making discovery almost inevitable. By default, some web servers (like older versions