Malakh Empire

The Malakh were a race who were at war with the Uvodni. The two races fought the Ghost Wars against each other, the Uvodni backed by an alliance of other races who were later crushed. Because of this, the Uvodni started abducting Human children from Earth and used them as soldiers. The two races eventually declared a truce and the war ended. The Malakh were known to Sarah Jane Smith, who considered them to be easily provoked. (SJA: Warriors of Kudlak)

It is unknown how Sarah Jane knows of the Malakh, she maybe learned about them from Mr Smith or encountered them either on an adventure on Earth or on her travels with The Doctor.