Search the system and grep out lines containing the word “password”. Other keywords you might like to use are “password=” “pass=” “username=” “user=” etc etc
grep --color=auto -rnw '/' -ie "PASSWORD" --color=always 2>/dev/null
Recursively grep keywords our of current directory
find . -type f -exec grep -i -I "PASSWORD" {} /dev/null \;
Find files with keywords in the filename
locate password | more
Find specific files, id: .bak, .conf, .cfg, id_rsa
find / -name *.bak -type f 2>/dev/null