Abnormal Security

Emerging

San Francisco AI email security (private, $5.1B valuation); $250M Series D (Wellington Management), behavioral AI detects novel BEC/phishing in Microsoft 365/Google Workspace competing with Proofpoint and Microsoft Defender.

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.

Founded
2018
Headquarters
San Francisco, California
Revenue
$5100M
Curated content • Fact-checked and verified

The Abnormal Security Story

Founded in 2018
San Francisco, California
Founded by Evan Reiser, Sanjay Jeyakumar

Founders

Evan ReiserSanjay Jeyakumar
Loading News...
Loading Timeline...
Loading Culture...
Loading Leadership...

Open Positions

Reddit Discussions

Loading Competitive Intelligence...

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.

Frequently Asked Questions

AI Visibility Rankings

How Abnormal Security performs in AI search results

AI Rank
?
Track your position
Platforms
5
ChatGPT, Gemini, Claude...
Visibility
?
Your mention rate
Premium Feature

Unlock AI Visibility Tracking for Abnormal Security

See exactly how Abnormal Security ranks across ChatGPT, Gemini, Perplexity, Claude, and Grok. Get actionable insights to improve your AI search performance.

Real-time Rankings
Track your position daily
Competitive Intel
See how you compare
Platform Breakdown
Per-AI performance
Actionable Insights
Optimize your visibility
Start Tracking for Free

Join 1,000+ brands · Free 7-day trial · No credit card required

Want to improve your AI visibility? Track performance across all major AI platforms.
Compare with Other Brands

Not So Random Others

Avast

Security
B2bCybersecurityGlobalSaasSecurity

Avast is a Prague-based cybersecurity brand — now part of Gen Digital Inc. (NASDAQ: GEN), formed from the $8.6 billion merger of NortonLifeLock and Avast in 2022 — providing antivirus, internet securi

HitPay

Finance
B2bPayment ProcessingSaasAsia PacificScaleup

HitPay is a Singapore-based all-in-one payment infrastructure company serving small and medium businesses across Asia-Pacific — enabling merchants to accept payments via QR code (PayNow, DuitNow, Prom

UpKeep

Field Service
B2bSaasSmb

UpKeep is a Los Angeles-based mobile-first maintenance management platform — backed with $60 million raised from Insight Partners, YC, 8VC, and others — providing CMMS (Computerized Maintenance Manage

Adobe Creative Cloud

Enterprise Software
B2bSaasCollaborationGlobalPublic

Adobe Creative Cloud is the flagship subscription product line of Adobe Inc. (NASDAQ: ADBE), encompassing over 20 professional creative applications including Photoshop, Illustrator, InDesign, Premier

Bamboo

Finance
B2bSaasAutomationEnterprise

Bamboo is a Lagos, Nigeria-based online brokerage platform — backed by Y Combinator (W20) with $19.4 million in total funding including a $17.4 million Series A in January 2022 from Tiger Global Manag

Crustdata

Data & Analytics
B2bSaasAi PoweredAnalytics

Crustdata is a B2B data infrastructure company that provides real-time APIs delivering fresh company and professional data for sales intelligence, go-to-market automation, and AI agent workflows. Trad

Compare Abnormal Security with Competitors

See how Abnormal Security stacks up against competitors in Security with side-by-side revenue, market share, and AI visibility data.

Start Comparison

Track Abnormal Security's AI Visibility in Real Time

Monitor how ChatGPT, Gemini, Perplexity, and Claude mention Abnormal Security. Get alerts when AI recommendations change. See competitive intelligence across all AI platforms.