USDoD said they gained access to the FBI’s InfraGard system by applying for a new account using the name, Social Security Number, date of birth and other personal details of a chief executive officer at a company that was highly likely to be granted InfraGard membership.

The CEO in question — currently the head of a major U.S. financial corporation that has a direct impact on the creditworthiness of most Americans — did not respond to requests for comment

USDoD told KrebsOnSecurity their phony application was submitted in November in the CEO’s name, and that the application included a contact email address that they controlled — but also the CEO’s real mobile phone number.

“When you register they said that to be approved can take at least three months,” USDoD said. “I wasn’t expected to be approve[d].”

But USDoD said that in early December, their email address in the name of the CEO received a reply saying the application had been approved (see redacted screenshot to the right). While the FBI’s InfraGard system requires multi-factor authentication by default, users can choose between receiving a one-time code via SMS or email.

“If it was only the phone I will be in [a] bad situation,” USDoD said. “Because I used the person[‘s] phone that I’m impersonating.”

USDoD said the InfraGard user data was made easily available via an Application Programming Interface (API) that is built into several key components of the website that help InfraGard members connect and communicate with each other.

USDoD said after their InfraGard membership was approved, they asked a friend to code a script in Python to query that API and retrieve all available InfraGard user data.

“InfraGard is a social media intelligence hub for high profile persons,” USDoD said. “They even got [a] forum to discuss things.”

KrebsOnSecurity shared with the FBI several screenshots and other data that may help isolate the imposter InfraGard account, but the agency declined to comment for this story.

To prove they still had access to InfraGard as of publication time Tuesday evening, USDoD sent a direct message through InfraGard’s messaging system to an InfraGard member whose personal details were initially published as a teaser on the database sales thread.

That InfraGard member, who is head of security at a major U.S. technology firm, confirmed receipt of USDoD’s message but asked to remain anonymous for this story.

While the data exposed by the apparent infiltration at InfraGard may be minimal, the user data might not have been the true end game for the intruders.

USDoD said they were hoping the imposter account would last long enough for them to finish sending direct messages as the CEO to other executives using the InfraGuard messaging portal. USDoD shared the following redacted screenshot from what they claimed was one such message, although they provided no additional context about it.