I'm not defending anything, although you clearly seem on the attack.
I worked for the company, I was not the decision maker. Many of us have worked at companies where decisions are made that are questionable or unethical, sometimes even illegal (although I don't believe this would have been illegal in my country at the time).
I've never worked someplace that paid criminals to do anything, and I'd resign before I did it. For one thing, who knows what my personal liability is. Much more importantly, it's plainly the wrong thing to do, and my society and community are in my hands as much as anyone else's.
I'm responsible for the consequences of my actions and the complexity of the world is not an excuse. Regardles, this question doesn't seem to fall in a grey area; they are obviously criminals who harm others; the company that paid them was not trying to fend off starvation, but simply wanted to test some software.
I worked for the company, I was not the decision maker. Many of us have worked at companies where decisions are made that are questionable or unethical, sometimes even illegal (although I don't believe this would have been illegal in my country at the time).