Abnormal Security

Abnormal Security is a cloud-native email security platform that leverages behavioral AI to protect organizations against the full spectrum of email-based attacks, including business email compromise (BEC), phishing, malware, ransomware, social engineering, and graymail. Founded in 2018 by CEO Evan Reiser and CTO Sanjay Jeyakumar, the San Francisco-based company has rapidly grown to achieve a $5.1 billion valuation as of its 2024 Series D funding round, backed by investors including Greylock Partners, Menlo Ventures, and CrowdStrike Falcon Fund.

Unlike traditional secure email gateways (SEGs) that rely on static rules, threat signatures, and known indicators of compromise, Abnormal takes a fundamentally different approach by using behavioral AI and machine learning to baseline normal communication patterns across an organization. The platform integrates directly via API with Microsoft 365 and Google Workspace, requiring no MX record changes, no gateway redirection, and no disruption to existing mail flow. This API-native architecture enables Abnormal to analyze both internal and external email communications, understanding organizational relationships, communication frequency, writing styles, authentication events, and supply chain interactions to build comprehensive behavioral profiles of every identity.

The platform's AI engine ingests thousands of signals per message — including sender behavior, recipient context, email content analysis, tone and sentiment, authentication metadata, and supply chain risk indicators — to detect anomalies that signature-based tools miss entirely. This is particularly effective against socially engineered attacks such as BEC, where there are no malicious payloads, links, or attachments to detect. Abnormal reports detecting up to 65% more BEC attacks compared to traditional solutions.

Beyond inbound email protection, Abnormal has expanded its platform to include Account Takeover Protection, which monitors for compromised accounts by analyzing sign-in events, mail filter rule changes, and anomalous email sending behaviors. The AI Security Mailbox automates the triage and response for user-reported suspicious emails, reducing SOC analyst workload by up to 95%. Security Posture Management provides visibility into email environment configurations and identifies misconfigurations. Email Productivity features automatically classify and remove graymail, newsletters, and promotional noise.

Abnormal serves over 2,000 enterprise customers across financial services, healthcare, manufacturing, technology, education, and government sectors. The platform is SOC 2 Type II certified, GDPR compliant, and supports HIPAA and FedRAMP requirements, making it suitable for highly regulated industries. With API-based deployment taking minutes rather than weeks, organizations gain immediate behavioral AI protection that complements or replaces their existing email security infrastructure.