The Swiss attorney general’s announcement that $4 billion may have been misappropriated from Malaysian state-owned companies opened a new front in the troubles facing 1Malaysia Development Bhd. Switzerland’s top prosecutor on Friday named a number of firms in Malaysia, Saudi Arabia and Abu Dhabi in relation to the matter, but gave no details of their roles, if any. The investigation is one of a series of global probes into 1MDB. A Malaysian government investigation last year found that almost $700 million entered Mr. Najib’s alleged bank accounts via agencies, companies and banks linked to 1MDB ahead of a close election in 2013.