Israeli Startup Rein Security Secures $25 Million to Protect AI Agents
Israeli startup Rein Security has raised $25 million in funding, pivoting its platform to secure enterprise AI agents against advanced prompt injection threats.
Israeli cybersecurity startup Rein Security has announced a $25 million funding round, less than a year after emerging from stealth with an initial $8 million seed round. Founded in 2024 by CEO Matan Bar Efrat and CTO Netanel Rubin, both alumni of Unit 8200, the company initially focused on general application security. However, following rapid market shifts, the startup pivoted to address the security of autonomous AI agents operating in cloud environments.
Securing Enterprise AI Agents
According to Rubin, the proliferation of self-developed enterprise AI agents created an unprecedented attack surface that existing security tools failed to address. This strategic pivot enabled Rein Security to multiply its Annual Recurring Revenue (ARR) eightfold. The platform provides real-time visibility into every action taken by cloud-based AI agents, monitoring incoming user prompts, generated responses, and backend executions.
The attacker registered as a legitimate company with a legitimate website, and when the agent accessed the site to learn about it, it was hit by a prompt injection attack embedded in the website's content, and started pulling confidential data belonging to other customers.
Preventing Large-Scale Data Leaks
Rubin revealed that the platform recently thwarted a sophisticated cyberattack targeting a Fortune 500 financial analytics client. The system detected anomalous behavior in real-time, preventing the unauthorized extraction of sensitive customer data through indirect prompt injection.
The latest financing round was co-led by Glilot Capital Partners and Sienna Venture Capital, with participation from Corner Ventures, Atlacle, and RNP Capital Advisors, bringing the company's total capital raised to $33 million.
