The malware that thoroughly penetrated Sony Pictures Entertainment was so sophisticated it likely would have worked against nine out of 10 security defenses available to companies, a top FBI official told members of Congress.

The comments, made under oath Wednesday by Joseph Demarest, assistant director of the FBI's cyber division, are the latest to largely let Sony officials off the hook. Last month's rooting of servers operated by Sony's movie division is believed to have exposed more than 100 gigabytes of data, including not only unreleased movies but, more importantly, personal details on tens of thousands of employees. Speaking before the Senate Banking, Housing, and Urban Affairs Committee, Demarest's apologist comments closely resembled those reported earlier this week from the CEO of Mandiant, the security firm investigating the breach on behalf of Sony.

"The level of sophistication is extremely high and we can tell...that [the hackers] are organized and certainly persistent," Demarest said, according to IDG News. "In speaking with Sony and separately, the Mandiant security provider, the malware that was used would have slipped or probably gotten past 90% of Net defenses that are out there today in private industry and [likely] challenged even state government."

The comments don't sit well with some security professionals, who say they appear to allow Sony to hide behind a veil of persistent threats posed by determined and well-resourced hackers. While successful hacks happen to just about everyone, careful planning can often contain the damage they inflict and limit the data available to people who gain unauthorized access. So far, Demarest, Mandiant, and Sony have declined to provide any specific details about exactly what makes the malware "unprecedented."