We are excited to announce that Greylock led a $24M Series A investment in Abnormal Security, a company initiated and incubated in 2018 at Greylock offices. Founded by Evan Reiser and Sanjay Jeyakumar, two exceptional technologists and entrepreneurs, Abnormal is officially launching their product today: a next generation cloud email security platform that leverages data science to protect organizations from sophisticated targeted email attacks, including unknown threats that existing solutions miss.

Abnormal Security co-founders Evan Reiser and Sanjay Jeyakumar

Large and Evolving Market, New Cloud-Native Architecture

Email continues to be the primary channel for business communication, and a significant point of egress for sensitive content. The email vulnerability landscape has evolved from volume-driven spam and phishing attacks to sophisticated spear-phishing and business email compromise attacks. The volumetric and signature based approaches used by incumbent email security vendors do not effectively prevent these highly targeted attacks — which require a semantic understanding of user and organizational behavior to prevent. As a result, customers have a significant unsolved vulnerability. Business email compromise is the leading driver of cyber crime in the United States with $2B+ in annual reported losses (FBI estimates).

At the same time, enterprises are undergoing a secular move to cloud/SaaS including cloud-based email (Office 365 and G-Suite). There is a significant opportunity to deliver a next generation email security solution with an API-based, cloud-native architecture.

Next-Generation, Data Science Based Approach

The Abnormal Security platform takes a data science approach to providing comprehensive email protection, detection and response, centered around Abnormal Behavior Technology (ABX). ABX incorporates more sources of data than any other email security solution today. Using an API-based integration, ABX analyzes email, organizational structure, event information, threat intelligence and more. Critically, the Abnormal API integration also provides full visibility into internal email traffic — existing email security gateway solutions are blind to internal email traffic.

Today, Abnormal Security’s product is live in production at a growing number of customer accounts including Fortune 500 enterprises, successfully protecting and preventing advanced email threats.

World-Class Team

Evan Reiser (CEO) and Sanjay Jeyakumar (CTO), the Abnormal Security founders, are talented technology executives who built large scale machine learning platforms at TellApart, Twitter and Google. The company is growing a very strong team including individuals and executives from Twitter, Google, Amazon and leading security companies including Palo Alto Networks, Proofpoint, FireEye and Duo. Learn about open positions here.

The Abnormal board of directors includes Rajiv Gupta, SVP Cloud, McAfee. We backed Rajiv in two prior entrepreneurial journeys (Skyhigh and Securent) and Abnormal is very fortunate to have Rajiv as a board member.

Greylock has a special history of partnering with entrepreneurs to initiate and incubate companies in markets where we have deep domain expertise. Some examples include Workday, Palo Alto Networks, Sumo Logic, TellApart and Awake Security. Abnormal is the latest in a distinguished list of innovative security companies that Greylock has partnered with over the years, including Palo Alto Networks, Okta, Imperva, OpenDNS, Skyhigh Networks, Demisto; and more recently and currently Awake Security, Cato Networks, Obsidian Security and Sqreen.

We’re thrilled and privileged to back the Abnormal team and look forward to continuing to partner with them closely as they build the industry’s leading next generation cloud email security platform.


Saam Motamedi

Saam partners with enterprise software entrepreneurs at the seed and early stages who are focused on new opportunities in intelligent applications, cybersecurity, AI, and data infrastructure.

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Asheem Chandna

Asheem seeks a partnership with founders who have identified a problem in enterprise, cybersecurity or infrastructure software and are eager to apply rigorous thinking to build a path-breaking solution – even if the value proposition has yet to fully emerge.

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