/usr/share/man/man1/estfxmantotxt.1.gz is in hyperestraier 1.4.13-3ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man1/estfxfilter.1.gz
/usr/share/man/man1/estfxfilter.1.gz