Abnormal Security

What is Abnormal Security?

Abnormal AI is an AI-native cybersecurity platform that protects organizations from advanced email and identity-based attacks by analyzing human behavior. It uses machine learning to build behavioral models for every user and vendor, detecting anomalies like phishing, business email compromise, and account takeovers in real time. By focusing on how people normally communicate and interact, it can identify subtle threats that traditional security tools miss, helping enterprises prevent cyberattacks and secure cloud applications more effectively.

Founded in 2018 by machine learning engineers Evan Reiser (former CEO of AdValid and Product Lead at Twitter) and Sanjay Jeyakumar (former Lead Architect at TellApart and Senior Software Engineer at Twitter) in San Francisco, California, Abnormal Security has raised over $540 million in total funding, achieving a valuation of $5.1 billion and surpassing $200 million in annual recurring revenue (ARR). Backed by top-tier venture firms including Wellington Management, Insight Partners, Greylock Partners, and Menlo Ventures, Abnormal protects over 2,400 global enterprises and 17% of the Fortune 500—including Xerox, Autodesk, Choice Hotels, and Mattel. Processing tens of billions of behavioral signals, its Human Behavior AI engine detects anomalies across identity, language, and vendor communications in milliseconds.

• Founder / Leadership: Evan Reiser (Co-founder & CEO) and Sanjay Jeyakumar (Co-founder & CTO)
• Launch Year: 2018 (Expanded globally with Series D in 2024–2026)

Use Cases:

• Stopping advanced zero-payload Business Email Compromise (BEC), executive impersonation, and payroll diversion attacks that bypass legacy email gateways
• Detecting and neutralizing compromised vendor and supply chain partner accounts modifying payment instructions via VendorBase
• Identifying compromised internal user accounts across Microsoft 365, Google Workspace, Slack, and Okta via behavioral telemetry
• Automating user-reported phishing mailbox triage and executing autonomous post-delivery message clawbacks without manual SOC intervention

Technology:

• Cloud-native API integration architecture deploying in under 60 seconds with zero MX record modifications or mail flow disruptions
• Human Behavior AI engine evaluating thousands of behavioral, identity, content, and relationship signals per message
• VendorBase global federated graph cross-referencing communication patterns, invoicing histories, and reputational risk across thousands of vendors

Target Users:

• Enterprise CISOs and cybersecurity leads looking to retire expensive, complex legacy secure email gateways (SEGs)
• IT directors and messaging engineers managing large-scale Microsoft 365 and Google Workspace corporate deployments
• SOC managers and incident responders overwhelmed by manual phishing investigation queues and false-positive reports
• Content creators using writing tools to draft corporate cybersecurity governance frameworks, vendor risk disclosures, and incident post-mortems

Corporate Entity: Operates as Abnormal Security Corporation (San Francisco, CA & Global)

Key features of Abnormal Security

Abnormal Security's key features are

• Human Behavior AI Engine: Analyzes identity profiles, login histories, communication frequencies, and natural language intent to establish what is normal and instantly flag abnormal behavior.
• One-Click Cloud API Deployment: Integrates directly with Microsoft 365 and Google Workspace in less than a minute via native APIs, eliminating the need to alter MX records or maintain mail routing rules.
• Advanced BEC & Executive Impersonation Defense: Detects sophisticated zero-payload social engineering tactics, including display name spoofing, urgent requests for wire transfers, and payroll rerouting scams.
• VendorBase Supply Chain Defense: Continuously monitors communications from third-party partners and suppliers, identifying compromised external vendors and altered banking details before invoices are paid.
• Account Takeover Protection (ATO): Automatically detects compromised corporate accounts across email, identity providers (Okta, Entra ID), and messaging apps (Slack, Teams), terminating sessions and revoking access instantly.
• AI-Automated Phishing Mailbox (Abnormal Abuse Mailbox): Autonomously analyzes employee-reported phishing emails in seconds, quarantining confirmed threats and clustering similar messages across all enterprise inboxes without human SOC review.
• Multi-Channel Collaboration Security: Extends behavioral threat detection beyond traditional email to protect modern cloud collaboration apps including Slack, Microsoft Teams, and Zoom.
• Explainable AI Incident Summaries: Generates transparent, human-readable case summaries explaining exactly why a message or account was flagged as malicious, detailing anomalous indicators across identity, content, and behavior.

Abnormal Security Pricing

Abnormal Security operates on an annual per-mailbox subscription model structured around core email protection, account takeover security, and extended collaboration modules with volume enterprise discounting.

Core Inbound Email Security:

• Typically ranges from approximately $2.50 to $4.00 per mailbox/month (~$30 to $48/mailbox/year; includes core inbound email protection, BEC defense, VendorBase supplier defense, and Automated Phishing Abuse Mailbox)

Complete Human Risk / Full Suite Licensing:

• Typically ranges from approximately $4.50 to $7.50 per mailbox/month (~$54 to $90/mailbox/year; bundles Email Protection with Account Takeover Protection, Cloud Collaboration security for Slack/Teams, and multi-tenant management)

Enterprise & Multi-Tenant Volume Quotes:

• Custom quote for organizations with 1,000+ mailboxes, offering tailored onboarding, proof-of-value retrospective threat audits, dedicated Customer Success Managers, and custom API limits

Disclaimer: Abnormal Security offers a 90-day historical Risk Assessment that connects in minutes via API to reveal threats missed by current security layers. Visit abnormal.ai for an official enterprise demonstration and customized proposal.

Who is using Abnormal Security?

Abnormal Security is designed for modern enterprise organizations and security teams seeking automated email defense, including

• Fortune 500 Enterprises & Global Corporations: Replacing cumbersome gateway appliances with modern API-first behavioral AI to safeguard hundreds of thousands of mailboxes
• Financial Institutions & Accounting Firms: Preventing multi-million-dollar wire fraud and vendor payment redirection schemes across high-volume transaction channels
• Hospitality & Retail Brands: Defending distributed operational teams against gift card scams, payroll update phishing, and corporate brand impersonation
• Technology & SaaS Scaleups: Protecting engineering workspaces and executive communications across Microsoft 365, Google Workspace, Okta, and Slack
• Content Creators: Using writing tools to draft corporate cybersecurity governance frameworks, vendor risk disclosures, and incident post-mortems
• Enterprise SOC Teams: Eliminating hours of daily manual email ticket processing by deploying autonomous abuse mailbox investigation and automated clawbacks

Best Abnormal Security Alternatives

Some of the strongest Abnormal Security alternatives include

• Proofpoint
• Mimecast
• Microsoft Defender for Office 365
• Ironscales
• Tessian
• Cisco Secure Email

Pros and Cons of Abnormal Security

Pros

• Rapid, frictionless API deployment integrates with Microsoft 365 or Google Workspace in under 60 seconds with zero MX record disruption
• Exceptional detection accuracy for text-based, zero-payload BEC and supplier invoice fraud that lack traditional malicious links or attachments
• VendorBase provides unmatched global supply chain visibility, assessing vendor risk across thousands of connected organizations
• Automated Abuse Mailbox saves hundreds of SOC hours monthly by triaging and clustering user-reported phishing emails autonomously
• Explainable AI incident summaries provide transparent, easy-to-understand breakdowns of exactly why an attack was blocked

Cons

• Because it is an API-based system, incoming messages land briefly in the inbox before being clawed back in milliseconds, which traditionalists may find unfamiliar
• Does not offer built-in 100% SLA mailbox continuity or long-term immutable compliance archiving like Mimecast
• Requires cloud-hosted email architectures (Microsoft 365 or Google Workspace); does not support legacy on-premises Exchange servers
• Premium pricing structure commands an investment typically suited for mid-market and enterprise organizations

Why Choose Abnormal Security?

Abnormal Security is the premier choice for organizations that want to eliminate the administrative burden of legacy email gateways and deploy modern, behavioral AI that stops sophisticated social engineering attacks.

• Sets up in minutes via native cloud APIs without requiring risky DNS changes or email downtime
• Understands human relationships and communication context to stop zero-payload executive impersonations
• Protects against compromised supply chain partners and billing fraud via global VendorBase intelligence
• Automates employee phishing report triage to reclaim hundreds of hours for Tier-1 SOC analysts
• Backed by a $5.1B enterprise valuation, tier-1 venture capital, and trusted by 17% of the Fortune 500

Abnormal Security vs. Competitors

The main difference between Abnormal Security, Proofpoint, Mimecast, and Microsoft Defender for Office 365 is that Abnormal Security is an API-first Human Behavior AI platform that deploys in seconds without MX record changes to stop sophisticated social engineering and vendor fraud, whereas Proofpoint relies heavily on traditional secure email gateway (SEG) filtering and broad human risk DLP, Mimecast emphasizes 100% SLA mailbox continuity and immutable compliance archiving, and Microsoft Defender for Office 365 is natively bundled within the Microsoft 365 ecosystem. Abnormal stands out for its frictionless setup, behavioral machine learning, and automated SOC mailbox triage.

How do we rate Abnormal Security?

Abnormal Security Review

Abnormal Security represents a paradigm shift in the email cybersecurity market. For decades, organizations were forced to route all incoming messages through cumbersome secure email gateways that analyzed static headers and known malicious links, leaving them vulnerable to socially engineered attacks that contain zero malware payloads. Abnormal recognized that stopping modern cybercriminals requires understanding human communication context. By integrating directly into cloud mail systems via API and establishing a behavioral baseline for every employee, Abnormal catches executive impersonations, vendor invoice fraud, and account compromises with surgical precision. Its automated abuse mailbox feature transforms SOC operations, reducing manual email triage workloads by up to 95%. For modern enterprises seeking effortless deployment and premier protection against human-targeted attacks, Abnormal Security is an exceptional platform.

Conclusion

Abnormal Security is an industry-leading AI-native human behavior security platform that completely redefines enterprise protection across cloud email and collaboration tools. By uniting 1-click API integration, behavioral machine learning, VendorBase supply chain defense, and autonomous phishing mailbox remediation into an intuitive cloud workspace, it eliminates the operational headaches and vulnerabilities of legacy email gateways. While organizations needing mailbox continuity or on-premises Exchange support will pair it with complementary tools, Abnormal Security’s behavioral detection precision, rapid time-to-value, and zero-maintenance architecture make it an indispensable cybersecurity platform.