The United States (US) Department of Justice's mushrooming investigation into the scandal-ridden Malaysian state fund 1MDB has extended to Deutsche Bank, two people familiar with the matter said on Thursday.The big German bank, which announced deep job cuts earlier this week and is embroiled in other high-profile government probes, says it is cooperating with the investigation and maintains that it is a victim in the scandal.The Justice Department is looking into whether Deutsche Bank br