I'm still trying to get to the bottom of this, but in a nutshell:
Some friends of someone very close to me are in a WhatsApp group and one of them posted that his account had been hacked. He then asked everyone not to send him any messages and to refrain posting in the group.
Later that day, the someone very close to me received a message from another very close friend in that group saying that they had just had hundreds of thousands of pesos stolen that very day, but didn't go into any more detail.
I'm being vague for obvious reasons and later today I'm hoping to find out if there is any link between the two occurrences.
From my research so far, some of this has to do with mysterious messages asking WhatsApp users to confirm a pin code to an unknown email account, which is also related to very fast battery drain.
More info to follow.