Police raided a house in northern Penang state late Sunday after receiving a distress call from a family member and found a group of eight people lying on top of the girl in a bedroom, said district police chief Azman Abdul Lah.
The girl was face down under the human pile, which comprised her parents, grandmother, uncle, aunt, two cousins and their Indonesian maid, he said.
The room was dark and chanting could be heard from under a blanket covering the group, Azman said.
The girl died of suffocation, and all eight involved have been detained, he added.
Belief in the supernatural has long been entrenched among Malaysia's main Malay, Chinese and Indian ethnic communities, though occult rituals have waned in recent decades.
Deaths linked to such rituals are occasionally recorded. Two Malay cousins were sentenced to 10 years in prison in 2010 for killing the parents of one of them during a spiritual cleansing ritual in that involved beating the slain couple with brooms and motorcycle helmets.