This site is a collation of Joseph Cohen of Russia. This site also includes descent from Chae Molochock, who was married to Joseph. As I have no other information about her family at this time, creating separate line of descent would be completely redundant with that of her husband.
The family is sometimes listed as coming from Pinsk in Poland. However, unless this refers to generations back beyond those we know of, Pinsk lay in the Russian Empire, not Poland. It was annexed from the Polish-Lithuanian Commonwealth in 1793 at the hands of Austria, Prussia and the Russian Empire. The map image is a segment from the Cambridge Modern History Atlas showing part of the Russian Empire at about the time of Joseph with the location of Pinsk marked.
The information comes from various Cohen descendants, both in my line and others.