Retaya

Retaya was a male Flaxian assassin, who was hired by the Tal Shiar in 2371 to kill Garak. He failed his attempt, and was subsequently executed by the Tal Shiar for crimes against the Romulan Star Empire. 

Quark asked DS9 Security chief Ro Laren in 2376 if she knew about Retaya. She didn't, though she was familiar with others who had threatened Quark's life in the past.