AI cybersecurity startup RunSybil completes $40 million funding

AI cybersecurity startup RunSybil has completed a $40 million financing round, led by Khosla Ventures, with participation from S32, Anthropic's Anthology Fund, Menlo Ventures, Conviction, and Elad Gil. Angel investors include Nikesh Arora, Amit Agarwal, Jeff Dean, and several founders and executives from OpenAI, Palo Alto Networks, Stripe, and Google.

RunSybil was co-founded in 2023 by Ari Herbert-Voss, OpenAI's first security researcher, and Vlad Ionescu, former head of offensive security red team at Meta. Its core product is the AI agent Sybil, which continuously and automatically performs penetration testing on applications running online, discovering, exploiting, and documenting real security vulnerabilities without human intervention. Currently, RunSybil's clients include startups such as Cursor, Turbopuffer, Notion, Baseten, and Thinking Machines Lab, as well as several large enterprises.