Cybersecurity firm FireEye says it has been breached by nation-state attackers. FireEye CEO Kevin Mandia revealed the hack in a blog post this afternoon. Mandia says the company has created “countermeasures” to detect or block the tools. The New York Times reports Russia is believed to be behind the attack. The attack raises age-old concerns about determined attackers’ ability to crack even the most advanced security organizations, Mandia said in the post. The company is providing methods and ways to detect any malicious use of the stolen tools.”]