New York-based Adaptive Security has raised US$43 million in series A funding, co-led by OpenAI’s startup fund and Andreessen Horowitz.

This marks OpenAI’s first investment in a cybersecurity firm.

The company simulates AI-driven social engineering attacks like fake calls, texts, and emails to train employees and assess organizational vulnerabilities.

The funding will help expand its engineering team and enhance the platform, which already supports over 100 customers.