The fifth plenum comes ahead of a major party congress next year, where Chinese President Xi Jinping is almost certain to secure a historic fourth term and oversee a leadership reshuffle.
Indonesian President Prabowo Subianto told his Cabinet last week that MSCI was trying to "intimidate" Indonesia, but said the country would not be afraid.
Social media posts had alleged that former Indonesian deputy foreign minister Dino Patti Djalal and political science professor Saiful Mujani met Singapore ambassador Kwok Fook Seng at his residence on Oct 18.
Japan's GMO Internet Group is compensating customers for losses stemming from unauthorised access following a cyberattack on its foreign exchange trading service.