/usr/lib/firefox/distribution/ is in firefox-locale-te 28.0+build2-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/firefox/distribution/searchplugins/
/usr/lib/firefox/distribution/searchplugins/locale/
/usr/lib/firefox/distribution/searchplugins/locale/te/
/usr/lib/firefox/distribution/searchplugins/locale/te/amazondotcom.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/creativecommons.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/duckduckgo.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/eBay-in.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/google.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/wikipedia-te.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/wiktionary-te.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/yahoo-in.xml