Abnormal AI

CybersecurityFounded 2018- HQ today: Las Vegas, Nevada, United States

Founders

Who Founded Abnormal AI?

Evan Reiser, Sanjay Jeyakumar · Founded 2018 · HQ today: Las Vegas, Nevada, United States

Who founded Abnormal AI?

Abnormal AI was founded by Evan Reiser, Sanjay Jeyakumar in 2018. It is now led by Evan Reiser.

Founders: Evan Reiser, Sanjay Jeyakumar
Founded: 2018
Headquarters: Las Vegas, Nevada, United States
Number of founders: 2
Current CEO: Evan Reiser (since 2018)

Where was Abnormal AI founded?: Abnormal AI was founded in San Francisco, California in 2018.
When was Abnormal AI founded?: Abnormal AI was founded in 2018.
Who started Abnormal AI?: Abnormal AI was founded by Evan Reiser and Sanjay Jeyakumar.
How old is Abnormal AI?: Abnormal AI is 8 years old as of 2026.

Founding Story

Evan Reiser and Sanjay Jeyakumar worked together on machine learning systems at TellApart and Twitter; Reiser had co-founded AdStack, which TellApart acquired, and Jeyakumar was a founding engineer at TellApart before it was bought by Twitter. They started the company in late 2018, incubated at Greylock's offices, under the name Abnormal AI. They soon renamed it Abnormal Security because, Reiser later wrote, the market did not yet take AI-named security companies seriously. It came out of stealth in November 2019 with a $24 million Series A led by Greylock.

What each Abnormal AI founder did

Founder	Role at founding	Contribution
Evan Reiser	Co-founder and Chief Executive Officer	—
Sanjay Jeyakumar	Co-founder	—

Evan Reiser

Background

Reiser started his career doing machine learning research and development at Eastman Kodak. He holds a B.S. in Computer Systems Engineering from Rensselaer Polytechnic Institute.

Role at Abnormal AI

Evan Reiser co-founded Abnormal in 2018 and has led it as CEO from its launch through its 2024 Series D at a $5.1 billion valuation and the 2025 rebrand to Abnormal AI. Before Abnormal he led product management and machine learning teams for Twitter's advertising business. He co-founded Bloomspot, which JPMorgan Chase acquired, and AdStack, which TellApart acquired. (Exact birth year remains publicly undisclosed).

Sanjay Jeyakumar

Background

Jeyakumar was a founding engineer at TellApart, which Twitter acquired, and earlier a lead engineer at Google working on search technology and the launch of Android.

Role at Abnormal AI

Sanjay Jeyakumar co-founded Abnormal in 2018 and was its CTO when the company launched in 2019. Before Abnormal he was the systems architect at Twitter responsible for the distributed data processing and machine learning systems behind Twitter's business. (Exact birth year remains publicly undisclosed).

Abnormal AI: CEO & Leadership History

Full timeline →

Evan Reiser

Co-founder and Chief Executive Officer

2018 – Present

As CEO, he successfully raised massive venture capital rounds, achieving a $3 billion valuation by proving that traditional rules-based email security was entirely incapable of stopping AI-generated phishing.

Keep researching Abnormal AI

Who Founded Abnormal AI? FAQ

Who founded Abnormal Security and when?

Evan Reiser and Sanjay Jeyakumar founded Abnormal in 2018. It was incubated at Greylock's offices and launched in November 2019.

What did Evan Reiser do before Abnormal?

Reiser led product management and machine learning teams for Twitter's advertising business, co-founded Bloomspot (acquired by JPMorgan Chase) and AdStack (acquired by TellApart), and started his career at Eastman Kodak.

What did Sanjay Jeyakumar do before Abnormal?

Jeyakumar was systems architect at Twitter for its distributed data processing and machine learning systems, a founding engineer at TellApart, and a lead engineer at Google on search and the Android launch.

How did the founders raise their first funding?

Abnormal launched in November 2019 with a $24 million Series A led by Greylock, where partner Asheem Chandna sits on its board.

Who founded Abnormal Security?

The company was co-founded by Evan Reiser and Sanjay Jeyakumar, who recognized the massive vulnerability in modern cloud email architectures.

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Compare founding stories, origins, and entrepreneurial journeys

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Explore Abnormal AI

Core profile pages, founders and related research hubs for this company.

Who founded Abnormal AI?

Founding Story

What each Abnormal AI founder did

Evan Reiser

Background

Role at Abnormal AI

Sanjay Jeyakumar

Background

Role at Abnormal AI

Abnormal AI: CEO & Leadership History

Keep researching Abnormal AI

Who Founded Abnormal AI? FAQ

Who founded Abnormal Security and when?

What did Evan Reiser do before Abnormal?

What did Sanjay Jeyakumar do before Abnormal?

How did the founders raise their first funding?

Who founded Abnormal Security?

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