  We report neutron diffraction studies of FeS single crystals obtained from
Rb$_x$Fe$_{2-y}$S$_2$ single crystals via a hydrothermal method. While no
$\sqrt {5}\times \sqrt {5}$ iron vacancy order or block antiferromagnetic order
typical of Rb$_x$Fe$_{2-y}$S$_2$ is found in our samples, we observe $C$-type
short range antiferromagnetic order with moments pointed along the $c$-axis
hosted by a new phase of FeS with an expanded inter-layer spacing. The N\'{e}el
temperature for this magnetic order is determined to be 165 K. Our finding of a
variant FeS structure hosting this $C$-type antiferromagnetic order
demonstrates that the known FeS phase synthesized in this method is in the
vicinity of a magnetically ordered ground state, providing insights into
understanding a variety of phenomena observed in FeS and the related
FeSe$_{1-x}$S$_x$ iron chalcogenide system.
