Abnormal AI, formerly Abnormal Security, was founded in San Francisco in 2018 and uses behavioural AI to stop phishing, business email compromise and account takeover in cloud email. It raised a $250 million Series D in August 2024 at a $5.1 billion valuation.
At a glance
| Price from | Custom |
| Best for | Microsoft 365 and Google Workspace customers fighting phishing |
From Abnormal AI's own website.
What stands out
- API-based, no mail rerouting
- Strong focus on business email compromise
Worth knowing
- Email is the core product
- No new primary round since its Series D
How it ranks
Abnormal AI is ranked 3rd of 10 in Best Cybersecurity Startups (Lister Score 94.4).
#3 in Best Cybersecurity Startups · Lister Score 94.4
Abnormal AI was named to the CNBC Disruptor 50 list in May 2026..
| Rank | Best Cybersecurity Startups | Score |
|---|---|---|
| 1 | Cyera | 96.9 |
| 2 | Island | 95.7 |
| 3 | Abnormal AI | 94.4 |
| 4 | Cato Networks | 93.2 |
| 5 | Vanta | 92.0 |
| 6 | Upwind | 90.7 |
| 7 | Chainguard | 89.5 |
| 8 | Huntress | 88.2 |
| 9 | Tines | 86.9 |
| 10 | Torq | 85.6 |
Frequently asked questions
How does Abnormal AI rank on Lister?
Abnormal AI is ranked 3rd of 10 in Best Cybersecurity Startups (Lister Score 94.4).
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