Mandiant, the cybersecurity firm that in February released a ground-breaking report detailing the suspected activities of a Chinese military hacking unit, told CNBC on Wednesday it is suffering the consequences of going public.
The firm said it saw "very aggressive reconnaissance" of its online systems after it published the report, which focused on a Shanghai-based Chinese Army unit known as the 2nd Bureau of the People's Liberation Army (PLA) General Staff Department's 3rd Department.
(Read More: China to US on Hacking: You've Got No Proof)
And over the past 10 days, the firm's chief security officer said, Mandiant has found itself under a sustained distributed denial of service attack from computers based in China. "The attack has been sustained, and it's been directed out of China for the most part," said Richard Bejtlich, Mandiant's chief security officer.
However, he cautioned that Mandiant cannot say for sure who is behind the attack—or whether it even comes from the Chinese army unit singled out in its report.