vicious

(of persons or their actions) able or disposed to inflict pain or suffering; "a barbarous crime"; "brutal beatings"; "cruel tortures"; "Stalin's roughshod treatment of the kulaks"; "a savage slap"; "vicious kicks"

having the nature of vice

bringing or deserving severe rebuke or censure; "a criminal waste of talent"; "a deplorable act of violence"; "adultery is as reprehensible for a husband as for a wife"

marked by deep ill will; deliberately harmful; "poisonous hate"; "venomous criticism"; "vicious gossip"