Русско-англо-русский юридический словарь

A fraudster is someone who commits the crime of fraud. [mainly British] (COBUILD Advanced English Dictionary)

defrauder is a person who causes injury or loss to someone through fraud or deceit (TransLegal)

In our opinion, a general audience might find “fraud perpetrator” a bit clunky. For alternatives, consider a term that’s in American dictionaries, “defrauder.” And if your readers would accept a bit of informality, you might occasionally stick in a “deceiver” or a “swindler” (even a “fraudster” or two). (Grammarphobia)