Business email compromise cybersecurity startup Abnormal Security Corp. revealed today that it has raised $50 million in new funding to double the size of its machine-learning and data science teams.

The Series B round was led by Menlo Ventures and included Greylock. Although the valuation on the deal was not officially disclosed, Forbes, quoting a source familiar with the deal, said it was on a $500 million valuation.

Founded in 2018 and launched in 2019, Abnormal Security offers a data science and behavioral analysis platform designed to protect organizations from sophisticated, targeted email attacks. That platform uses a unique composite analysis of identity, relationships and email content to stop attacks that lead to account takeover, financial damage and organizational mistrust.

Abnormal says it’s disrupting the market by using artificial intelligence to reinvent email security for large enterprise customers that want email cloud security solutions not requiring tuning or maintenance. They also want to stop the attacks that bypass legacy secure email gateways.

The company’s platform deploys to Microsoft 365 and Google Workspace environments through native application programming interface integrations with its AI threat detection engine. That engine analyzes a diverse set of data about people, relationships and business context to understand abnormal behavior and block socially engineered attacks.

Abnormal has seen strong growth in 2020 fueled by the growing importance of email security after enterprises shifted to remote work during the COVID-19 pandemic. During the year, Abnormal has tripled its Fortune 500-level customer base and its annual recurring revenue. Customers include Xerox Holding Corp., DirectBuy Home Improvement Inc., Z Gallerie, One Kings Lane Inc., Alliance Data Systems Corp. and Sur La Table Inc.

“There is clear evidence that conventional email solutions are insufficient,” Evan Reiser, co-founder and chief executive of Abnormal Security, said in a statement. “The shift in attacker techniques to more personalized, socially-engineered attacks requires a different approach. No amount of threat intelligence can stop an attack that’s never been seen before. The only way to do so is through AI-based behavioral detection.”

Including the new funding, Abnormal Security has raised $75 million to date.

Image: Abnormal Security