This is an insider job , not outsider attack.
Is an insider really going to risk their potentially well-paying job (along with even more severe legal consequences) for what amounted to only a little over $100,000? That's not exactly a great payout for hijacking a large server network, and any insider would know that the situation would get caught and disabled relatively quickly, before much money could be made. It only really makes sense for someone unrelated to the company with less chance of getting caught to attempt something like that.
And as the article points out, this Java exploit (or rather Apache exploit) doesn't require physical access to the systems to be performed. This recently-revealed exploit is being called one of the most serious security vulnerabilities ever, and all sorts of businesses and government agencies worldwide have been getting their servers hacked in recent weeks.
It's the result of a bug in popular open-source server software that's been present and overlooked in the code for the better part of the last decade. If there's any "inside job" involved, it would be with flaws getting purposely introduced into open-source code by contributors, though it could just as easily be an accidental oversight in the code. A lot of companies and organizations like to believe that open-source software is somehow immune from serious flaws, but realistically, there are likely numerous flaws like this that have been hiding in the code that runs the internet for years. When a particular piece of software sees such widespread use, such flaws coming to light can cause widespread security breaches around the globe. And it can often take weeks or potentially even months for an organization to get all their servers patched.