Moisei Sosner was born in 1900 in Vitebsk. Before the war began, he moved to Moscow with his wife Roza and their two children. In 1943, at the age of 43, he was conscripted as a private but was later promoted to be the commander of an ammunition supply department. The highest rank Sosner reached was that of senior sergeant.
Sosner did not receive any orders of distinction but he was awarded some medals. The citation that accompanied the Medal of Military Merit that he was awarded in October 1943 stated: "… during the fighting for the city of Chernigov and of the forced crossing of the Dnieper River he continued to supply our advanced units with ammunition, often delivering it under enemy fire." The citation that accompanied second medal, this time For Bravery, in August 1944, was similar, but included two additional details: Sosner captured some enemy ammunition (81-mm mortar mines), which was then used against the enemy. In that year, he wrote in the diary that he kept during the war: "It was a great pleasure [for me] to see the Fritzes mowed down with their own ammunition." Furthermore, Sosner was not only a supplier of ammunition, he was also a sapper. According to his diary, more than once he took part in combat.
While advancing with his unit and entering newly liberated towns from Orel in Russia to Poland, Sosner tried to learn about the fate of Jews under the Nazi rule in each area. Hearing accounts of the mass murder of local Jews sometimes made this strong man cry. He also felt a great desire for revenge.
Sosner was killed in battle near Wismar, in German Pomerania on May 4, 1945, just four days before the end of the war.