"...in a media we don't mention..."
The Bangkok Post reported that a couple of days ago, also.
It's got to be your phone (or your government), not the SIM, it's not an automatic download from Dtac. I have a Dtac SIM so I get the Dtac app but do not have the app you mention. It cannot be courtesy of Dtac, if it was, everyone on Dtac would have it also.