From there, they caused as much trouble as possible. The entire corporate system locked up, showing a red skeleton that announced as bluntly as possible, "You've been hacked by #GOP." Hard drives were wiped, email accounts froze and employees were cautioned not to connect to the office Wi-Fi. Sony Pictures employees were forced to do business on landlines and fax machines, according to The LA Times.
But while Sony struggles to regain control of its data, the attackers seem more interested in spreading chaos than causing lasting damage. Lots of sensitive financial information was shared in the file dump, but it's unlikely any of it will be used for identity theft simply because it was made available so publicly, attracting the attention of the FBI at a very early stage. Other data, like employee salaries and scripts in development, seem more likely to cause PR damage than lasting financial harm.
That's not to say Sony isn't suffering. This has certainly been an intense week for the studio and anyone who works there, and it remains to be seen how much the early torrent leaks will cost the company at the box office. But unlike recent breaches at Home Depot and various government agencies, the purpose of this attack wasn't to steal money or extract compromising information. At every stage, the attackers' goal was to make life miserable for Sony Pictures employees, causing as much noise as possible along the way. If they made the attack noisy enough and scary enough, we might listen the next time North Korea rattles its sabers and back off.
It's not a particularly noble or intricate plan, but judging by the headlines, it seems to be working.