Abnormal Security, a San Francisco-based AI-security firm, secured $250M in Series D funding, valuing the company at $5.1 billion.

The round was led by Wellington Management with existing investors Greylock Partners, Menlo Ventures, Insight Partners, and CrowdStrike Falcon Fund participating.

Funds will be used for expanding operations and further development of their AI-native platform that protects against sophisticated cyber attacks.

Founded by CEO Evan Reiser, Abnormal Security uses machine learning to understand human behavior and detect risks in cloud email and applications. The platform integrates with Microsoft 365 and Google Workspace and extends protection to other cloud applications like Slack and Salesforce.

With over 2,400 organizations using their platform, including 17% of the Fortune 500, Abnormal Security aims to continue its global expansion and achieve FedRAMP compliance.