black magic 
noun [mass noun]
Magic involving the supposed invocation of evil spirits for evil purposes.In rural areas, difficulties in pregnancy are often blamed on evil spirits or black magic....
- Wrestlers wore amulets to ward off evil spirits and black magic from their opponents.
- I don't know whether you believe in witchcraft, sorcery, black magic, and all that kind of thing.
Synonyms
sorcery, magic, witchcraft, wizardry, necromancy, enchantment, spellworking, incantation, the supernatural, occultism, the occult, the black arts, devilry;
malediction, voodoo, hoodoo, witching, witchery, hex, spell, jinx;
North American mojo, orenda;
New Zealand makutu
South African informal muti
rare sortilege, thaumaturgy, theurgy