Nebulock lands $25M to hunt AI-era threats before they strike
What's the deal? Boston-based cybersecurity startup NebulockDealroom has a profile for this one. Try Dealroom → has raised a $25 million Series A led by FirstMark, founder and chief executive officer Damien LewkeDealroom has a profile for this one. Try Dealroom → told Axios Pro exclusively.
Existing backers Bain Capital Ventures, Decibel PartnersDealroom has a profile for this one. Try Dealroom →, Zetta Venture PartnersDealroom has a profile for this one. Try Dealroom →, and Step FunctionDealroom has a profile for this one. Try Dealroom → also joined the round, announced June 25, 2026.
Nebulock builds an AI-native platform that hunts threats across endpoint, identity, cloud, network, and SaaS environments. It analyses behavioural patterns to flag malicious activity before it becomes an incident.
Why now? Bad actors increasingly use AI to blend into normal workflows, making attacks harder to spot.
"Breaches used to take months. Now they take tokens," said co-founder Ron Cahlon, pointing to AI agents that operate with legitimate access and rarely trip an alert.
Nebulock says it has run more than 300 million agentic investigations and delivered over 4,000 high-confidence findings, earning trust from Fortune 500 teams in finance and healthcare.
What could go wrong? The bet rests on catching threats hidden in normal-looking behaviour — a far harder problem than triaging known bads.
Cybersecurity is also crowded, with incumbents like CrowdStrike and Palo Alto Networks racing to add their own AI defences. Nebulock's founders hail from those very companies, plus Arctic Wolf.
The signal: Dealroom pegs Nebulock at breakout stage barely two years after launch, a trajectory that tracks with its founders' pedigree from CrowdStrike, Palo Alto Networks, and Arctic Wolf. With lead investor FirstMark and AI-focused backer Zetta Venture PartnersDealroom has a profile for this one. Try Dealroom → writing the cheque, the round reflects mounting conviction that defending against agentic threats demands proactive hunting rather than reactive alerting.
Read more: Axios · The SaaS News
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