Ripple account transfers 50 million XRP to unknown address

According to Bithomp data, Beijing time on April 11th at 8:20:20, from the Ripple account address to rPfSrrKY97EihgZeAwqgR7g1tYzDDJoAys address transfer 50 million XRP, worth about 17.66 million US dollars. The transaction ID is: 5B49FA8966DA5FE462D342F36BD194193ACFE17AA36CC89C581E5779C3EF5867.