Edward Snowden successfully assumed the electronic identities of top NSA officials to access some of the secret National Security Agency documents he leaked, Richard Esposito, Matthew Cole and Robert Windrem of NBC News report.

“Every day, they are learning how brilliant [Snowden] was,” a former U.S. official with knowledge of the case told NBC. “This is why you don’t hire brilliant people for jobs like this. You hire smart people. Brilliant people get you in trouble.”

The 30-year-old’s role as a “system administrator” meant that he was able to access NSAnet, the agency’s intranet, using those user profiles and without leaving any signature.

An official told NBC that the NSA identified several instances in which the elite NSA-trained hacker impersonated officials, and that the spy agency’s forensic investigation is “trying to figure out which higher level officials Snowden impersonated online to access the most sensitive documents.”

His role as system administrator also meant that he had the ability to download files from his computer to an external storage device — Snowden reportedly downloaded tens of thousands of classified documents onto thumb drives before flying from Hawaii to Hong Kong on May 20.

“The damage, on a scale of 1 to 10, is a 12,” a former intelligence official told NBC.

On Monday Esposito and Cole reported that Snowden functioned as a “ghost user,” meaning that he was able “look at any file he wanted, and his actions were largely unaudited.”

Last week Michael Isikoff, Cole, and Esposito reported that the NSA is “overwhelmed” does not know the full extent of the tens of thousands of documents the former NSA contractor took from its system.

Snowden is currently living in Russia.

Source: Business Insider