/usr/share/avant-window-navigator/applets/comics/feeds/xkcd.feed is in awn-applet-comics 0.4.1~bzr1507-0ubuntu7.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | # Feed description
name=xkcd.com
url=http://xkcd.com/rss.xml
|