The National Security Agency's (NSA) former chief hasn't retired just yet.

After leaving the agency in March, Keith Alexander is now pitching his cyber consultant services to the country's biggest financial institutions. It'll cost them, though. Alexander is reportedly asking for up to $1 million per month, according to Bloomberg.

During his meetings, Alexander emphasizes the potential destruction attackers could wreck on financial data, as well as the amount of money and information hackers could steal if they gained access to company servers.

A contract is supposedly in the works with the Securities Industry and Financial Markets Association (SIFMA) for about $600,000 per month.

"What I'm concerned about is we're going to have a 9/11 in cyberspace,” Alexander told Bloomberg. “We don't need to suffer this kind of attack.”