Some of the most powerful espionage tools created by the National Security Agency's elite group of hackers have been revealed in recent days. A cache of hacking tools with code names such as Epicbanana, Buzzdirection and Egregiousblunder appeared mysteriously online over the weekend, setting the security world abuzz with speculation over whether the material was legitimate. The file appeared to be real, according to former NSA personnel who worked in the agency's hacking division, known as Tailored Access Operations (TAO). The exploits are not run-of-the-mill tools to target everyday individuals. They are expensive software used to take over firewalls, such as Cisco and Fortinet, that are used in the largest and most critical commercial, educational and government agencies around the world," said [former TAO operator] Blake Darche. Some former agency employees suspect that the leak was the result of a mistake by an NSA operator, rather than a successful hack by a foreign government of the agency's infrastructure. It is not unprecedented for a TAO operator to accidentally upload a large file of tools ... one of the former employees said. "What's unprecedented is to not realize you made a mistake," he said. "You would recognize, 'Oops, I uploaded that set' and delete it." Critics of the NSA have suspected that the agency, when it discovers a software vulnerability, frequently does not disclose it, thereby putting at risk the cybersecurity of anyone using that product.