Proofpoint acquires rival Hornet security for over $1 billion to promote Europe’s expansion before IPOs

The cybersecurity company’s proof point is its biggest deal to date, as it has acquired German cybersecurity company Hornet Security for over $1 billion and is expanding in Europe and preparing to return to the open market.

This move will help Proof Point cement its European presence and provide a stronger foothold in the managed service provider (MSP) market. It will also set the stage for a return to the open market. This is a plan that has been quietly lined up since becoming private in 2021.

Proof Point, owned by private equity giant Thomas Bravo, confirmed the acquisition Thursday. The company told CNBC that the transaction is stepping up its offering for small and medium-sized businesses, particularly those relying on MSPs for cloud-based email protection, data loss prevention and Microsoft 365 security.

The acquisition “helps integrate fragmented security tools into a unified platform that protects people and advocates data across a global threat landscape,” Proofpoint CEO Sumit Dhawan told CNBC.

Cybersecurity integration is taking the pace as businesses rush to keep up with the threat of AI fuel. Proofpoint’s deal is the latest in a series of well-known acquisitions. In March, Google agreed to buy the Cloud Security Startup Wiz for $32 billion, and last month, Palo Alto Networks announced plans to acquire AI-centric Protect AI.

Headquartered in Honnover, Hornetsecurity has established a strong position in the European market, serving over 125,000 SMBs with a team of over 700 employees. The company focuses on email security and compliance, making it the number one concern for businesses caught up in the intersection of AI-driven attacks.

“Generative AI fundamentally changes the threat landscape, allowing faster, more targeted and more complex attacks,” Dhawan said in an interview with CNBC. He added that small businesses need “increasingly at intersections” and “integrated, highly efficient” security platforms.

Dhawan described the acquisition as a way to simplify and integrate fragmented security tools. “It helps to integrate fragmented security tools into a unified platform that protects people and protects data across a global threat landscape,” he said.

This is not just a move to strengthen the product. Proofpoint is looking to be made public again. The company’s leadership said last year it was weighing external funds against acquisitions as part of a broader strategy to return to the stock market by 2026. This horn security transaction is clearly a step in that direction.

“Hornetsecurity brings a very strong business to Proofpoint, targeting new market segments for MSPs and diversifying routes to the market,” says Dhawan. “This will be a stronger company and business as we explore a return to the open market as we make a significant contribution to our future revenue and cash flow.”

Proofpoint itself employs over 4,500 people and counts 85% of the Fortune 100 as its customers. Hornetsecurity’s transactions are scheduled to close in the second half of 2025, with normal closure conditions pending.

The acquisition also highlights a broader trend in cybersecurity: integration. Large companies are acquiring smaller players to keep them competitive in industries where AI exceeds both innovation and threat. Just this year, Google said it would acquire Cloud Security Startup Wiz for $32 billion, while Palo Alto Networks announced plans to purchase AI Protect AI, an AI-focused security startup.

For Proofpoint, this transaction is not just about scale. It’s about staying ready for what comes next.

Private equity giant Thomas Brothers acquired Proof Points in April 2021 for $12.3 billion.