Company Overview
About Abnormal Security
Abnormal Security is a San Francisco, California-based AI-native cloud email security company — founded in 2018 by Evan Reiser (CEO) and Sanjay Jha (CTO), both former Google engineers — using behavioral AI to detect and block business email compromise (BEC), phishing, ransomware, account takeovers, and AI-generated social engineering attacks against enterprise email environments (Microsoft 365, Google Workspace) through approximately 600 employees. The company raised a $250 million Series D funding round at a $5.1 billion valuation, led by Wellington Management with participation from existing investors Greylock Partners, Menlo Ventures, Insight Partners, and the CrowdStrike Falcon Fund — bringing Abnormal's total funding to approximately $580 million. Abnormal Security's approach to email security is fundamentally different from traditional signature and rule-based approaches: rather than scanning emails for known malware hashes or suspicious links against threat databases, Abnormal's AI models each employee's historical communication behavior (who they email, how they write, what times they send messages, what financial requests they make) and flags deviations from established baselines as anomalies requiring investigation — enabling detection of novel BEC attacks that have no prior signature, AI-generated phishing that passes link reputation checks, and vendor invoice fraud that impersonates legitimate suppliers.
Business Model & Competitive Advantage
Abnormal Security's behavioral AI email security model creates detection capability that signature-based competitors cannot match for the highest-impact email threats: a business email compromise attack where a cybercriminal compromises a CFO's email account and sends a wire transfer request to the treasury team uses legitimate email infrastructure (the actual CFO account), sends to known internal recipients, contains no malicious links or attachments, and passes every signature and URL reputation filter — but Abnormal's behavioral baseline detects that the wire transfer request is unusual (abnormal amount, unusual recipient bank, request to skip approval workflow) and quarantines the email before the $5 million transfer is executed. Abnormal's API-based cloud integration (connecting to Microsoft 365 and Google Workspace via API, not requiring email flow redirection through Abnormal's infrastructure) enables deployment without changing email routing or MX records — removing the friction that historically made enterprise email security deployments require weeks of DNS configuration.
Competitive Landscape 2025–2026
In 2025, Abnormal Security competes in cloud email security and AI threat detection against Microsoft Defender for Office 365 (the default Microsoft 365 security layer), Proofpoint (private, Thoma Bravo portfolio, $1B+ revenue, legacy email security leader), and Mimecast (private, Permira portfolio) for enterprise security spending on email threat protection. The $5.1 billion valuation at the Series D (2025) positions Abnormal as one of the highest-valued enterprise security unicorns, reflecting enterprise customer demand for AI-native email security that replaces aging signature-based systems. The CrowdStrike Falcon Fund participation provides a strategic partnership signal — Abnormal Security integrates with CrowdStrike's endpoint detection and response platform, enabling correlation between email threat intelligence and endpoint behavior for unified attack investigation. The 2025 strategy focuses on expanding the security platform beyond email to cover collaboration tools (Microsoft Teams, Slack), cross-channel human behavior modeling, and global enterprise account growth in the Fortune 2000 market where AI-generated BEC attacks are becoming the primary financial loss vector.
The Abnormal Security Story
Founders
Company Timeline
Major milestones in Abnormal Security's journey
Leadership Team
Meet the leaders behind Abnormal Security
Evan Reiser
Evan Reiser is CEO and co-founder of Abnormal Security. He previously led product management and machine learning teams for Twitter's advertising business and co-founded several successful companies including Bloomspot (acquired by JPMorgan Chase) and AdStack (acquired by TellApart). He combines deep ML expertise with proven entrepreneurial success.
Sanjay Jeyakumar
Sanjay Jeyakumar is the CTO and co-founder of Abnormal Security, responsible for the company's AI-native behavioral security platform architecture. He brings extensive expertise in artificial intelligence, machine learning, and security systems to drive Abnormal's technical innovation.
Smita Sanadhya
Smita Sanadhya joined Abnormal as CFO in March 2024. She is a former executive at Microsoft Hong Kong, HP, and startup Okta, bringing deep financial and operational expertise to guide Abnormal's growth trajectory and prepare for potential public markets.
Jeff True
Jeff True serves as Abnormal's Chief Legal Officer, joining from Zoom where he led the legal department. He brings extensive experience in corporate law, compliance, and governance for high-growth technology companies.
James Yeager
James Yeager leads Abnormal's public sector sales efforts, bringing extensive cybersecurity sales experience from CrowdStrike. He focuses on protecting government agencies and public sector organizations from sophisticated email threats.
Open Positions
Reddit Discussions
Key Differentiators
Emerging Innovator
Abnormal Security is an emerging player bringing innovative solutions to the Security market.
Enterprise Scale
With $5100M in revenue, Abnormal Security operates at enterprise scale with proven market validation.
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