Phone credit transfers
> So, please pardon my ignorance when I ask, is this transfer of credit from one PAYG phone to someone else's account a facility which is specific to Indonesia, or is it more widespread?
Widespread - I used to work for a company which did this with clients in Malaysia, the Philipines, Vietnam, India and Mexico.
No idea about the reality or otherwise of the virus, but SMS based phone credit transfers - and to a lesser extent real world purchasing - are big business.