While robots.txt is not a security mechanism (it only requests bots to not index, it does not prevent access), it is a basic hygiene step. Use it to ask Googlebot to ignore your log directories:
: A standard identifier keyword commonly found in credential logs, configuration settings, or database dumps. allintext username filetype log passwordlog facebook install
The string includes facebook install . That suggests the log might be from: While robots
to help you manage your credentials