As the comments mentioned, the 'samech mem' is the abbreviation for 'Samael' - the Yetzer Hara/Angel of Death/Archangel of Esav. You can find more written about it here as the article discusses
The angel's prosecution of Yaakov (and the Jewish nation as a whole)
The sa'ir l'azazel given on Yom Kippur which goes to the angel.
The angel's role as Esav's ...