The epicenter of the quake was 62 miles north of Langsa, Sumatra, Bernama reported.
In Penang, workers on the upper floors of a 65-story building in George Town felt the quake.
A spokesman for the security division at the complex said workers on the lower floors didn't feel anything.
The quake was felt in Thailand's southern Phuket province, the Thai News Agency reported.
A spokesman for Phuket's Provincial Disaster and Mitigation Office said people in high-rise buildings felt the quake but the overall situation in the resort province and adjacent areas remained normal.