RunSybil, an AI-native offensive security platform, has raised $40M in Series A funding led by Khosla Ventures. The Sybil platform deploys AI agents to autonomously discover and exploit vulnerabilities in applications and infrastructure through black-box testing. The capital will fuel platform development and hiring of engineers and hackers.
AI Pentesting Wave Builds Momentum
The raise aligns with rising investor interest in AI-driven security testing. Veria Labs secured $3.2M in seed funding, while Horizon3.ai has raised over $100M total. Pentera amassed $157M. RunSybil's black-box AI agents target chained vulnerabilities across code, APIs, cloud, and infrastructure that scanners miss.
Manual Pentests Fail AI Speed
Traditional penetration testing relies on periodic manual efforts, inadequate for continuously evolving applications. Breaches demand proactive validation on every deployment. The penetration testing market stands at $2.72B in 2026, per Mordor Intelligence.
AI Agents Mimic Elite Hackers
Sybil's AI agents perform continuous testing without code access, reasoning like skilled red-teamers to chain vulnerabilities and uncover business logic flaws. This approach yields 90% fewer false positives than traditional tools. Unlike signature-based automation from Pentera or infrastructure-focused NodeZero from Horizon3.ai, Sybil handles full-stack simulations.
As Ariel Herbert-Voss, CEO and co-founder, noted:
"We check every box that needs to be checked—for auditors, regulators and compliance teams."
Khosla Backs Frontier Security
Khosla Ventures led the round, joined by S32, Anthropic's Anthology Fund, Menlo Ventures, Conviction, Elad Gil, and angels including Nikesh Arora and Jeff Dean. This investor mix signals conviction in AI's role against escalating cyber threats. Vinod Khosla highlighted the frontier nature of AI pentesting.
As Vinod Khosla noted:
"What it takes to add security and penetration testing to the AI world is definitely frontier—RunSybil is on the edge."
Pentesting Market Scales Rapidly
The sector grows from $2.72B in 2026 to $5.54B by 2031 at 15.3% CAGR, driven by AI enabling attacker-like reasoning at scale, according to Mordor Intelligence. Competitors like Mindgard ($11.9M raised) focus on AI model security, while RunSybil broadens to general apps and infra. CISA's CTEM framework pushes continuous threat exposure management.
Founders Bring Tier-1 Expertise
Co-founder and CEO Ariel Herbert-Voss was OpenAI's first security researcher, contributing to GPT-3 and Codex security. CTO Vlad Ionescu led Meta's Offensive Security Group, founding Red Team X and scaling it significantly. Their combined AI and red-teaming pedigrees enable Sybil's hacker intuition automation.
Hiring Surge Targets Growth
Post-funding, RunSybil accelerates hiring of hackers and engineers in San Francisco and New York. Recent additions include a founding engineer and security experts. This builds on customers like Notion, Cursor, and Fortune 500 firms for national expansion.