It is found in North Asia and the Russian Far East, Estonia, and Japan, where it grows on the lobes of the lichens Flavocetraria cucullata and Cetraria islandica.

[1] The species epithet honours German lichenologist Josef Hafellner, "in recognition of his important contribution to the knowledge of lichenicolous fungi".

Having had the opportunity to collect and observe more specimens, he noted the constancy of the coloured spores, and concluded that the traits of genus Endococcus are better aligned with the characteristics of the fungus.

They are black and shiny and protrude slightly from the surface of the host lichen, measuring up to 50 μm in diameter.

[1] In Asian Russia, Endococcus hafellneri has been recorded from Buryatia, Sakha, the Magadan Oblast, and the Caucasus.