All those are likely candidates, you have to ask yourself, what is their motivation to do this particular job.
What a lot of people don’t understand is, most of the so called “hacks” are human hacks, meaning someone within the company knowingly or most times unknowingly has created the problem.
It could be some pissed off internal IT person who is behind this, I was contracted to a major worldwide Energy company when one of the guys on our small team, opened an infected email, fortunately before the virus got out of hand it was contained but this particular guy nearly lost his job over something that was another department’s screw up.
“Nude pics of hillary. Click here!”