Security firm FireEye is the latest victim of a cyberattack, and likely the victim of a state-sponsored attack.

FireEye is one of the leading cybersecurity firms, providing consulting, services, software and hardware to customers. The company has been involved in detecting and fighting multiple high-profile attacks. Its history and expertise make the news it was attacked all the more concerning.

CEO Kevin Mandia outlined the attack in a blog post:

Based on my 25 years in cyber security and responding to incidents, I’ve concluded we are witnessing an attack by a nation with top-tier offensive capabilities. This attack is different from the tens of thousands of incidents we have responded to throughout the years. The attackers tailored their world-class capabilities specifically to target and attack FireEye. They are highly trained in operational security and executed with discipline and focus. They operated clandestinely, using methods that counter security tools and forensic examination. They used a novel combination of techniques not witnessed by us or our partners in the past.

Mandia says the attackers used some of the company’s Red Team tools that FireEye uses to test its customers’ security. As a result, FireEye is releasing the necessary information for customers to mitigate the threat those tools now pose.

We are not sure if the attacker intends to use our Red Team tools or to publicly disclose them. Nevertheless, out of an abundance of caution, we have developed more than 300 countermeasures for our customers, and the community at large, to use in order to minimize the potential impact of the theft of these tools.

FireEye is working with the FBI and Microsoft to investigate the incident. Nonetheless, the fact that the attackers are using methods the company has never seen before is not very encouraging for the cybersecurity industry.