/usr/share/applications/firefox.desktop is in kubuntu-firefox-installer 12.04ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | [Desktop Entry]
Version=1.0
Name=Mozilla Firefox Browser Installer
GenericName=Mozilla Firefox Browser Installer
Exec=kubuntu-firefox-installer
Type=Application
Icon=firefox-installer
Categories=Qt;Network;
|