AI cybersecurity startup Armadin announced on October 1, 2026 that it had raised $255.5M in a Series B round. According to Reuters, the company's valuation exceeded $2.5B once the deal closed. The company said the round brings its total funding to date to $445M. The news was confirmed by the company's official announcement. Series B is the next major funding stage after the company's earlier rounds, and the list of participating funds was also disclosed.
Funding round and investors
The round was announced on the first day of October. Two major venture funds — Andreessen Horowitz and Accel — co-led the round. Bain Capital Ventures and Redpoint joined as new investors. In addition, investors known from earlier rounds took part: Google Ventures, Kleiner Perkins, Menlo Ventures and In-Q-Tel. According to Reuters, those funds had also participated in Armadin's previous funding rounds.
The $255.5M Series B is the largest round Armadin has raised to date. The company said total funding has reached $445M — meaning it had previously raised $189.5M. The investor lineup is notable: co-leads Andreessen Horowitz and Accel are among the largest players in the venture market, while Bain Capital Ventures and Redpoint invested in the company for the first time. The repeat participation of Google Ventures, Kleiner Perkins, Menlo Ventures and In-Q-Tel shows the confidence of earlier investors in the company.
Where the money will go
Armadin said it will spend the new funds across four areas. The first is scaling the platform: the company plans to deploy its swarm-of-AI-agents security platform at a larger scale. The second is research: scientific work on improving agentic attack methods will continue. The third is hiring: the company intends to expand its engineering and research teams. The fourth is go-to-market: sales and marketing efforts will be intensified to bring the product to more corporate and government customers.
According to the company's official statement, the funds will be allocated across exactly these four areas — platform, research, hiring and go-to-market. Scaling the platform means preparing the existing product to operate in more customers' systems. The research track includes further improving agents' offensive capabilities. Hiring means attracting and training new specialists. The go-to-market track covers expanding the sales team and working with new customers.
What the company does and its founder
Armadin uses a swarm of AI agents that act like hackers to find vulnerabilities in corporate systems. In other words, the company specializes in testing systems with AI agents playing the role of real attackers, finding gaps before an attack occurs. A 'swarm of agents' means many AI agents acting simultaneously and independently: each probes different parts of a system and reports the vulnerabilities it finds.
The company emerged from stealth just seven months ago. Nevertheless, according to its official statement, it is already running agentic attack campaigns in live systems for Fortune 500 enterprises and government clients. That is, the company's product is already in use in the real systems of large corporations and government agencies. An 'agentic attack campaign' is a set of systematic test attacks by AI agents against a specific organization's systems, aimed at identifying weak points in defenses.
Armadin is led by founder and CEO Kevin Mandia. He is a well-known figure in cybersecurity: he previously founded the cybersecurity company Mandiant, which he later sold to Google. With his new company, he is now working on fighting cyberattacks with the help of agentic artificial intelligence. The sale of his previous company to a major technology giant demonstrates his experience in the field.
Official statement
Armadin disclosed details of its customer base in its official announcement:
In its official announcement, Armadin said it emerged from stealth seven months ago and now runs agentic attack campaigns in live systems for Fortune 500 enterprises and government clients. PRNewswire
The statement was published on October 1 via PRNewswire and was also confirmed by Reuters. Both sources cite identical figures for the round size, valuation and the list of participating funds.
