According to persons familiar with the situation, Microsoft has agreed to buy RiskIQ, a security software company, as the tech giant strives to extend its products and better safeguard customers amid a rising flood of global cyber-attacks.

The sale might be disclosed as soon as the next few days, according to the people, who requested not to be identified because they were speaking about a private transaction. According to one of the sources, Microsoft will pay more than $500 million in cash for the company.

San Francisco-based RiskIQ makes cloud software for detecting security threats, helping clients understand where and how they can be attacked on complex webs of corporate networks and devices. Its customers include Facebook Inc., BMW AG, American Express Co. and the U.S. Postal Service, according to the company’s web site.

Known for its annual report on security called the “Evil Internet Minute," RiskIQ has raised $83 million from firms like Summit Partners and Battery Ventures, according to Crunchbase. It was founded in 2009.

A spokesman for Microsoft declined to comment and RiskIQ didn't immediately respond to a request for comment. Microsoft has been adding security features to products like Windows and its Azure cloud services to protect individual machines and detect attacks on networks. The company has also added personnel who probe Microsoft’s own products for vulnerabilities, help clients clean up after a cyberattack, and runs a lab called the Microsoft Threat Intelligence Center that closely tracks nation-state hackers.

The software maker has also acquired several companies to expand its security capabilities. Last month, Microsoft bought ReFirm Labs, a maker of technology to secure Internet of Things devices, for an undisclosed amount. In a blog post announcing the deal, the company said it has 3,500 employees working on security at Microsoft and a mission to help protect customers “from the chip to the cloud."

Microsoft and the rest of the U.S. technology industry, as well as companies and government agencies, have also spent the past eight months grappling with a series of damaging and widespread cyberattacks. This month, hackers launched a mass ransomware attack that exploited multiple previously unknown vulnerabilities in IT management software made by Kaseya Ltd. In March, hackers linked to China used flaws in the code of Microsoft Exchange to break into tens of thousands of organizations, and in an attack disclosed in December, suspected Russian hackers compromised popular software from Texas-based firm SolarWinds Corp., inserting malicious code into updates for SolarWinds software.