Founder Intelligence

Evan Reiser

Human behavior in the digital workplace is a high-dimensional pattern. Machine learning can model social relationships to stop social engineering attacks.

Role
Chief Executive Officer & Co-Founder
Country
United States
Company founded
2018
Status
Active

Known for

Abnormal AI provides enterprise-grade artificial intelligence solutions, delivering specialized Abnormal AI Platform technology designed to optimize…

Ecosystem Connection Map

How this founder connects across companies, products, industries, and research on Brel.

Overview

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Evan Reiser is an American machine learning engineer and entrepreneur who serves as Chief Executive Officer of Abnormal Security (Abnormal AI). Reiser pioneered the application of behavioral data science to email security, protecting Fortune 500 organizations from sophisticated business email compromise (BEC).

Why it matters

Reiser demonstrated how behavioral modeling and natural language understanding can solve socially engineered cyber threats that bypass traditional cryptographic security perimeters.

Editorial insight

Reiser translated adtech-era AI behavioral modeling into Abnormal Security, making human-behavior baselines a reference architecture for enterprise email and BEC defense.

Career & Timeline

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Education & Twitter Machine Learning

Reiser earned his B.S. in Computer Science from Washington University in St. Louis. He co-founded Bloomspot, a merchant analytics platform acquired by JPMorgan Chase in 2012, before joining Twitter to lead machine learning auction algorithms that processed billions of daily ad impressions.

Founding Abnormal Security & Behavioral AI

In 2018, Reiser and Sanjay Jeyakumar founded Abnormal Security. Recognizing that legacy email gateways could not detect text-only social engineering attacks, Reiser built an API-based behavioral AI engine that models internal employee communication graphs to detect identity impersonation in real time.

  • Company founded 2018 · founded Abnormal AI was founded in 2018 per the company profile source on file. Source
  • 2018: Founded in San Francisco by Evan Reiser and Sanjay Jeyakumar. 2018 · development Source
  • Product 2024 · product 2024u20132026: Expanded from email security into broader behavioral identity and AI governance capabilities per official product pages. Source
  • April 16, 2025: Company announced rebrand to Abnormal AI, Inc.; primary domain moved to abnormal.ai. 2025 · development Source

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Latest Developments

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  • 2024–2026: Expanded from email security into broader behavioral identity and AI governance capabilities per official product pages. Latest
  • Development 2018 · development Source

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FAQ

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Who is Evan Reiser?

Evan Reiser is an American machine learning engineer and entrepreneur serving as Chief Executive Officer and co-founder of Abnormal Security (Abnormal AI), the behavioral AI email cybersecurity platform.

What did Evan Reiser work on before founding Abnormal Security?

Reiser worked as a machine learning engineer building high-throughput ad-targeting systems, co-founded mobile ad exchange Bloomspot (acquired by JPMorgan Chase), and served as Product Manager for Twitter's multi-billion-dollar ad-auction platform.

Where did Evan Reiser study?

Reiser graduated with a Bachelor of Science in Computer Science from Washington University in St. Louis.

Sources & Verification

Verified
Last reviewed Aug 2026

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