Find out who made money by shorting it, there's your list of suspects, or at least co-conspirators (if this turns out to be a hack).
As long as securities react to hacks, there will be a massive incentive to 1) hack, and 2) overstate the hack's significance. Furthermore, as bots become more sophisticated, confusing them becomes easier. If you know bots will short CompanyX when "CompanyX hacked" hits the headlines, then you have an unfair advantage just by being the first to know of the hack.