RunSybil, an AI cybersecurity startup that uses AI agents to automatically hack company software to find security weaknesses, has secured $40 million in venture capital funding.
The round was led by Khosla Ventures, with participation from S32, the Anthology Fund from Anthropic and Menlo Ventures, Conviction and Elad Gil, along with angel investors including Nikesh Arora, Amit Agarwal, Jeff Dean, and other founders and leaders from companies including OpenAI, Palo Alto Networks, Stripe and Google.
The company did not disclose the valuation it achieved in the new funding round.
The company’s AI agent, Sybil, conducts continuous autonomous penetration tests against live applications—finding, exploiting and documenting real security vulnerabilities without humans in the loop. That’s different from other security tools currently making headlines, such as Claude Code Security, which analyzes source code in applications for known vulnerabilities before it is deployed.
RunSybil instead tests software that is already running, probing live systems the way a hacker would—by exploring systems, chaining vulnerabilities together and testing authentication boundaries to find paths to sensitive data.
