Amazon Web Services CEO Andy Jassy in an interview with CNBC's Jon Fortt at the 2017 AWS re:Invent conference in Las Vegas.

Amazon's cloud business has acquired Sqrrl, a cybersecurity start-up that spun out of the National Security Agency.

The deal, which Sqrrl confirmed on Tuesday, comes as Amazon Web Services aims to pick up more business from U.S. intelligence agencies. In November AWS announced the formation of a "secret" region of data centers meant to handle computing and data storage jobs from those clients.

"We will be joining the Amazon Web Services family, and we're looking forward to working together on customer offerings for the future," Sqrrl said in a message posted to its homepage. Axios reported in December that Amazon was in advanced talks to buy Sqrrl and said the deal could be worth more than $40 million. Terms weren't disclosed.

AWS leads the public cloud market, with $1.17 billion in operating income and $4.58 billion in revenue in the third quarter. Competitors include Google and Microsoft.

AWS has sought to enhance its cloud in the past year with security tools. In August AWS announced Amazon Macie, based on technology from a start-up it had acquired called Harvest.ai.

Sqrrl's team and underlying technology tie back to the NSA. In 2011, the agency open-sourced database software called Accumulo, and in 2012, "a group of the core creators, committers and contributors" of Accumulo founded Sqrrl, according to the start-up's website. Sqrrl, based in Cambridge, Massachusetts, raised capital from Spring Lake Equity Partners, Matrix Partners, Rally Ventures and Accomplice.

Companies use the Sqrrl software to pick up on existing threats.

"Sqrrl consumes and fuses diverse security datasets, including network traffic logs, DNS logs, proxy data, user directory and identity information, external intelligence feeds, and customer transactions," the company said in a data sheet. "Sqrrl uses this data to reveal suspicious behaviors, pinpoint the actors involved, and assess an organization's risk exposure."