Google has announced a massive $5.4 billion deal to acquire the cybersecurity firm Mandiant, Inc. The acquisition is subject to regulatory approval, but Google says it expects the deal to close later this year. If it goes through, it would be Google’s second-largest acquisition ever, slotting in between the $12.5 billion deal for Motorola Mobility and the $3.2 billion purchase of Nest. Mandiant will join the Google Cloud division.

Mandiant was founded in 2004 and does security consultancy and threat research. It makes an automated threat-monitoring system called the “Mandiant Advantage Platform.” Mandiant was a key researcher investigating many of the world’s biggest security incidents, like the SolarWinds supply-chain attack, the Log4j vulnerability, and the Pulse Secure VPN vulnerabilities.

Google has a ton of experience securing its own cloud. Besides bulking up Google’s security staff on its home turf, the goal of this deal is to bring more of that security know-how onsite with security consultancy services. The blog post lays out what the full Google Cloud security offering will look like:

  • Advisory services: Mandiant’s proven global expertise in providing comprehensive incident response, strategic readiness, and technical assurance helps customers mitigate threats and reduce business risk before, during, and after an incident.
  • Threat detection and intelligence: Mandiant’s experience detecting and responding to advanced adversaries offers customers actionable insights into the threats that matter right now.
  • Automation and response tools: Security operations tools within Google Cloud’s Chronicle, Siemplify solutions, and Mandiant’s Automated Defense help customers analyze, prioritize, and streamline threat response and leverage Mandiant’s expertise as a virtual extension of their teams.
  • Testing and validation: Mandiant Security Validation helps customers continuously validate and measure the effectiveness of cybersecurity controls across cloud and on-premise environments and complements Google Cloud’s Security Command Center to help ensure strong risk management.
  • Managed defense: Mandiant’s managed detection and response service acts as a seamless extension of customers’ security teams, delivering continuous monitoring, event triage, and threat hunting that’s agnostic to customers’ endpoint and network tooling.

Google Cloud making a huge acquisition is a bit of a surprise, as the division is in a distant third place behind Amazon and Microsoft in the cloud market. Canalys has Google at 7 percent of the worldwide cloud market share, with Microsoft Azure at 19 percent and Amazon Web Services at 32 percent.