AegisAI Raises $36 Million to Fight AI-Generated Phishing Emails

Key points

• AegisAI closed a $36 million Series A round on Thursday, bringing total funding to $49 million.
• Battery Ventures led the round, with Accel and Foundation Capital also participating.
• The San Francisco startup was founded in 2025 by two former Google security engineers who helped build reCAPTCHA and Safe Browsing.
• AegisAI's software connects to Microsoft 365 and Google Workspace to screen incoming email for phishing and fraud attempts.
• The company plans to use the money to expand its AI detection tools and push its Vanguard investigation agent into general release.

AegisAI, an email security startup founded in 2025, has raised $36 million in a Series A funding round led by Battery Ventures, with Accel and Foundation Capital also putting money in. The raise brings the company's total funding to $49 million since it came out of stealth in September 2025.

Co-founders Cy Khormaee and Ryan Luo both worked on Google's security team, where they helped build reCAPTCHA (the "I'm not a robot" check used across the web), Safe Browsing (the warning Google shows when you visit a dangerous site), and Web Risk (a similar tool for businesses). That background shapes what they are building now.

What problem is AegisAI trying to solve?

The company's core concern is AI-generated spear phishing: targeted fake emails where criminals use artificial intelligence to research a specific person, study their professional contacts, and write a convincing lure addressed directly to them. Until recently, that kind of personalised attack took significant effort. AI tools have made it fast and cheap.

Traditional email filters work by matching messages against lists of known-bad senders or suspicious phrases. AegisAI's platform takes a different approach. A network of AI agents reads each incoming message and tries to assess the intent behind it and whether the apparent sender is who they claim to be, rather than simply checking it against a rulebook.

The software connects to Microsoft 365 and Google Workspace through an API, meaning a programming link that lets two software systems talk to each other, without requiring businesses to change how their email is routed. The company says that keeps setup simple.

In March, AegisAI launched a companion tool called Vanguard. When a suspicious link or attachment arrives, Vanguard opens it the way a human reader would, observes what happens, and produces a written threat report within minutes.

What does this mean for ordinary email users?

Most people will never interact with AegisAI directly. It sits in the background of a company's email system. But the threat it targets is real and growing: a fake email that uses your boss's name, references a real project you are working on, and asks you to approve a payment or hand over a password.

"You cannot patch human trust," CEO Khormaee said in a statement. "If your security program still relies on template-based phishing tests and awareness training, you are training your people to spot last year's threat."

The new funding will go toward building out more detection agents, getting Vanguard to general availability, and expanding the company's sales operation, first reported by SecurityWeek.

If your employer uses Microsoft 365 or Google Workspace, ask your IT team whether your email system can flag messages that impersonate colleagues or senior staff. That one check catches a large share of business email fraud before it reaches your inbox.