(Reuters) -Cybersecurity firm F5 said on Wednesday it had detected unauthorized access to certain company systems by a highly sophisticated nation-state threat actor, but the breach had no impact on its operations.

The company discovered the intrusion on August 9 and took “extensive actions” to contain the threat, engaging external experts, including CrowdStrike, Mandiant, NCC Group and IOActive, to assist with the investigation, it said in a filing with the U.S. Securities and Exchange Commission.

F5, a provider of cybersecurity and multi-cloud application services, said the attacker had long-term access to its internal systems used to develop BIG-IP software and stole files containing parts of the program’s code and details about security flaws that had not yet been made public.

The c

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