I have just checked my deposit history on the Remitano platform. A popular exchange platform to sell cryptocurrence to cash in Vietnam. You can see my first deposit here:

The first deposit was made on December 28, 2017 and the transaction that nutildah gave:
It was made on December 12, 2017. So I guess at this point, I sold ETH directly to someone, because I haven't used Remitano yet.