1Malaysia Development Berhad (1MDB) was a Malaysian investment fund that was set up in 2009 by the Malaysian government to help Malaysia become a rich and developed country. Unfortunately, it was discovered in 2015 that a lot of people, including the prime minister, had been using the money from 1MDB for their own personal gain. This was a very bad thing because it was stealing from the Malaysian people and their money was not going towards things that helped Malaysia become a richer country. The scandal was so bad that the Malaysian government had to investigate it and punish the people responsible.