How to find files in a Debian system not installed or created by dpkg?
Solution 1:
Use the cruft
package:
cruft is a program to look over the system for anything that shouldn't be there, but is; or for anything that should be there, but isn't.
Solution 2:
You could try something like this:
dpkg -L --list-all-package-files | grep "^/usr" > dpkg-files.dat **(don't know the dpkg option "--list-all-package-files", read mand dpkg)**
find /usr -type f -o -type l > all-usr-files.dat
sort dpkg-files.dat all-usr-files.dat | uniq -c | grep " 1 "
This way you will get all files that are in /usr but not any package file. As a first shot this could help you.