OpenAI and Andreessen Horowitz Double Down on AI-Driven Cybersecurity with $43M Bet on Adaptive Security

Cybersecurity startup Adaptive Security has secured $43 million in Series A funding, led by OpenAI’s Startup Fund and Andreessen Horowitz (a16z), marking a watershed moment in the fight against AI-powered cyber threats. The round—announced in April 2025—highlights a critical inflection point in the cybersecurity industry, where traditional defenses are increasingly outmatched by adversaries weaponizing generative AI.

Ask Aime: What cybersecurity measures are investors looking at post-Series A funding for Adaptive Security?

The New York-based startup, founded by CEO Brian Long (a serial entrepreneur behind TapCommerce and Attentive), specializes in simulating and countering social engineering attacks like deepfake voice calls, AI-generated phishing emails, and SMS scams. Its platform combines live attack simulations, real-time threat triage, and AI-driven training modules to quantify and mitigate vulnerabilities. The funding will fuel hiring of engineers to expand these capabilities, as well as deepen partnerships with enterprises.

The urgency behind this investment is stark. Cybercriminals are industrializing deception with AI tools: a $25 million Hong Kong bank fraud orchestrated via AI voice cloning and a Ukrainian deepfake video targeting U.S. foreign policy underscore the escalating stakes. According to a recent survey of over 100 CISOs, 87% now rank AI-driven social engineering as their top concern.

Adaptive’s platform addresses this through five pillars:
1. AI Deepfake Simulations: Live voice/SMS/email attacks mimic real-world scenarios, training employees to spot fakes.
2. Real-Time Triage: Instant analysis of suspicious communications to prioritize responses.
3. AI-Generated Training: Modules rated 4.8/5 by employees, blending emerging threats with traditional risks.
4. Risk Scoring: Continuous assessment of vulnerabilities at individual, team, and organizational levels.
5. GenAI Content Tools: Automates policy drafting and compliance materials, cutting bureaucratic overhead.

The startup’s early traction is notable. With over 100 enterprise clients—such as Podium, First State Bank, and the Dallas Mavericks—within three months of its public launch, Adaptive has already proven demand. Yet its true test lies in scaling against entrenched competitors like Cyberhaven and Snyk, which also target AI-driven risks.

The investment from OpenAI signals a strategic shift. This is the AI giant’s first cybersecurity bet, aligning with its stated mission to mitigate risks from its own technology. “Adaptive’s platform isn’t just a product—it’s a necessary counterweight to the arms race we’re in,” said OpenAI’s Ian Hathaway. Meanwhile, a16z’s Zane Lackey called it “the first truly AI-native defense system.”

Market tailwinds favor Adaptive. The global cybersecurity market is projected to hit $500 billion by 2028, with AI-driven solutions commanding a growing share. Yet challenges remain. Enterprises wary of “AI fatigue” may resist adopting yet another platform, while regulatory uncertainty around AI’s use in defense could complicate scaling.

For investors, the bet hinges on Adaptive’s ability to scale its risk-scoring algorithms and maintain differentiation. The $43M round values the company at an undisclosed figure, but given the Series A check size and early customer wins, a $200-300M valuation post-funding seems plausible. Competitors like CrowdStrike and Palo Alto Networks trade at 15-20x revenue multiples; if Adaptive hits $50M ARR by 2026 (as its growth trajectory suggests), a $750M+ valuation isn’t out of reach.

Long’s vision—“delete your voicemail to stop voice cloning”—hints at the granular, behavioral shifts required to combat these threats. Adaptive’s success will depend on its platform’s adaptability: can it stay ahead of attackers iterating faster with open-source AI tools? The startup’s focus on quantifiable risk metrics (e.g., 30% reduction in simulated attack success rates among clients) offers a measurable path to validation.

In conclusion, Adaptive Security’s funding round isn’t just a vote of confidence in the company—it’s a recognition of an existential threat. With AI enabling unprecedented scalability in cyberattacks, enterprises have no choice but to adopt proactive, AI-native defenses. Adaptive’s combination of simulation, training, and real-time tools positions it as a leader in this space, though execution remains key. For OpenAI and a16z, this is a calculated play to own a piece of the next trillion-dollar cybersecurity frontier—one where the only defense against AI is better AI.