By Jonathan Davies
Cyber security giant Kaspersky Lab says its own systems were the subject of a hack.
The firm said the attack was designed to spy on some of its new technologies, and was carried out using three separate techniques not seen before.
Kaspersky Lab said although hackers gained access to some files, the data obtained was "in no way critical to the operation" of its new products.
"Spying on cybersecurity companies is a very dangerous tendency," said the company's chief executive Eugene Kaspersky.
"The only way to protect the world is to have law enforcement agencies and security companies fighting such attacks openly.
"We will always report attacks regardless of their origin."
Costin Raiu, director of Kaspersky Lab's global research and analysis team, said: "This highly sophisticated attack used up to three zero-day [previously unknown] exploits, which is very impressive - the costs must have been very high."