/usr/share/doc/trust-store/html/inherit_graph_4.md5 is in libtrust-store-doc 2.0.0+16.04.20160119-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1
833f26021077c6c25e1bf74b731f827e