AegisAI, a startup founded by former Google security executives Cy Khormaee and Ryan Luo, has raised a $36 million Series A led by Battery Ventures, with participation from Accel and Foundation Capital, bringing total funding to $49 million.

The company uses AI agents to detect and block AI-driven spear phishing attacks, which it says are increasingly bypassing traditional rule-based security systems.

Khormaee noted that AI-powered attacks now evade existing controls more than half the time, making them nearly twice as effective as before.

AegisAI‘s agents analyze each email contextually, catching anomalies like malicious PDF attachments with built-in passwords or CAPTCHAs that standard filters miss.

The startup has already been adopted by dozens of customers, including crypto payments company Mash, AI startup LangChain, and Google-owned privacy compliance platform Lokker.

Battery Ventures partner Dharmesh Thakker invested after observing a rise in email attacks, believing that AI-driven defense is a priority for companies.

While AegisAI faces competition from Lightspeed-backed Ocean and established vendors like Proofpoint and Mimecast, Thakker cited the founders’ experience securing Gmail as a differentiator.

The company plans to eventually expand into other areas of security, such as data protection, with the goal of using customized AI agents to become the next dominant security company.