First, I thought you were simply talking about insiders who had knowledge of targeted software. Here it seems like you're talking about moles being paid to insert new vulnerabilities.

But even then, I don't find this threat particularly credible. After all, what we're talking about here are W2 employees with social security numbers or immigration tracking committing galactically expensive torts against their employers and in all likelihood most of the Fortune 500, in addition to (in all probability) multiple felonies. How much money do you think Endgame can afford to pay these people to shoulder that risk? There's a reason this doesn't actually happen all the time.