For some time I've been a member of a Whatsapp group (Language Exchange group with very little activity) I joined through a URL. Last night, the group was "hacked" along with other groups sharing the same administrator. It seems the Whatsapp account of said administrator was compromised. I think the most likely explanation is that the administrator ran a script on his browser console to automate some task, and that this script turned out to be a malware that stole his session. I'm not talking about high-profile people here, so it is unlikely that someone would invest resources in a more sophisticated attack. Is there a more likely explanation?

This may seem like a somewhat banal question. But the most concerning aspect of this situation is of a more social nature. The affected people immediately start to draw conclusions about individuals they regard as unfriendly misfits. In two such incidents the "misfits" have been suffering from mental illness (one was in fact hospitalized when the incident occurred more than a year ago). People just start connecting unrelated dots about other recent instances of "hacking" with their limited information, and end up submitting vulnerable persons to further ostracism.