Skip to main content

RunSybil

Category: AI in Cybersecurity

An AI-native offensive security platform that utilizes autonomous agents to automate 'hacker intuition' for continuous penetration testing and vulnerability discovery. RunSybil was founded in 2023. The company is led by Ariel Herbert-Voss. Based in San Francisco, USA. Team size: 11-50. Total funding raised: $40.0M. Latest round: Series A ($40.0M, Mar 2026). Key investors include Khosla Ventures, S32, Anthology Fund (Anthropic), Menlo Ventures, Conviction, Elad Gil, Nikesh Arora, Amit Agarwal, Jeff Dean.

Founded
2023
Headquarters
San Francisco, USA
Team size
11-50
Total funding
$40.0M

Value proposition

Replaces periodic, manual penetration testing with continuous, AI-driven offensive simulations that identify and exploit vulnerabilities with the logic of a human attacker.

Products and solutions

Autonomous AI Hacking Agents, Continuous Penetration Testing Platform, Automated Red Teaming Engine, Vulnerability Exploitation & Validation Suite

Unique value

Founded by OpenAI's first security hire and Meta's former offensive research lead, the platform moves beyond static scanning to mimic the creative, multi-step reasoning of elite human hackers.

Target customer

Enterprise security teams, CISOs, and high-growth technology companies with complex digital infrastructures.

Industries served

Cybersecurity, Enterprise Software (SaaS), Financial Services, Cloud Infrastructure

Technology advantage

Leverages proprietary LLM-based agents trained on offensive security research (GPT-3/Codex lineage) to perform complex, chained attacks that traditional automated tools miss.

How they differentiate

Leverages proprietary LLM-based agents trained on offensive security research to automate 'hacker intuition,' enabling complex, multi-step chained attacks that traditional scanners and static tools miss.

Main competitors

Horizon3.ai, Pentera, Mindgard

Key partnerships

Khosla Ventures (Lead Investor), Anthology Fund (Anthropic-backed), Early enterprise design partners including Notion and Cursor, DEF CON AI Village (Founding ties)

Notable customers

Notion, Cursor, Turbopuffer, Baseten, Thinking Machines Lab, Undisclosed Fortune 500 companies, Undisclosed major financial institutions

Major milestones

Founded in 2023 by OpenAI's first security hire Ariel Herbert-Voss and Meta's offensive research lead Vlad Ionescu., Secured $40M Series A funding led by Khosla Ventures in March 2026., Successfully deployed autonomous hacking agents in production for major design partners like Notion and Cursor.

Growth metrics

Serving production enterprise customers including high-growth tech platforms and Fortune 500 financial institutions.

Market positioning

AI-native offensive security challenger focused on continuous, autonomous penetration testing for enterprise infrastructure.

Geographic focus

North America (HQ in San Francisco), Global Enterprise

Patents and IP

No specific registered patents disclosed; proprietary model weights and offensive research heuristics serve as core IP.

About Ariel Herbert-Voss

First security research hire at OpenAI; core research contributor to GPT-3 and Codex; Harvard Machine Learning PhD dropout; Co-founder of DEF CON AI Village.

Official website: