Bolster, creator of the CheckPhish phishing tracker, raises $14M led by Microsoft’s M12


A deceptive email containing a link that appears legitimate but is actually malicious remains one of the most dangerous and successful tricks in a cybercriminal’s arsenal. Now, an AI startup called Bolster, which has developed an innovative approach to combat this tactic, has raised $14 million in funding to expand its efforts. This includes enhancing its popular free phishing-checking portal, CheckPhish, as well as supporting its primary paying customers: brands and businesses.

Microsoft’s venture fund M12 led the round as a new investor, joined by Thomvest Ventures, Crosslink Capital, Liberty Global Ventures, Cheyenne Ventures, Cervin Ventures, and Transform Capital. Bolster has now raised a total of approximately $40 million, though it has not disclosed its current valuation.

Bolster’s business model revolves around providing brand and URL checking services to businesses that frequently email their customers and are prime targets for malicious hackers aiming to impersonate them or use their branding to sell counterfeit products. Bolster’s clients include major companies such as Dropbox, Uber, LinkedIn, and Coinbase. According to the Cybersecurity Infrastructure Security Agency, phishing is the starting point for over 90% of all cyberattacks, which can lead to data breaches, network infiltrations, or device infections.