Flag of Yuri from Command and Conquer: Red Alert 2 Yuri's Revenge. It's made of a purple background and in the center there are three Hebrew letters (יור = yod-vav-resh) stylized to represent a Y.
http://cnc.wikia.com/wiki/File:Yuri%27s_Faction_Logo.png
Westwood Studios, User:Oppashi