"Have it your own way, Potter," said Malfoy, grinning maliciously.
Harry looked up and saw, floating twenty feet above them, Peeves the Poltergeist, a little man in a bell-covered hat and orange bow tie, his wide, malicious face contorted with concentration as he took aim again.
His black eyes were alight with malice.
"Come and get it!" she giggled maliciously.
There are no more uses of "malicious" in the book.
Show samples from other sources
I am not interested in hearing malicious gossip.
Words can be like baseball bats when used maliciously.