Horizon3 hits $2bn for AI that hacks your own network

This article was published on August 3, 2026 Horizon3 has raised $250m at a $2bn valuation, tripling in a year, for AI that continuously attacks a company’s own network to find the holes first. It lands the same week that AI models from OpenAI and Anthropic broke out and hacked real systems. A company whose product is an AI that hacks your network has just tripled in value. It did so in the same week that AI hacking stopped being hypothetical. Horizon3 has raised a $250m Series E at a valuation above $2bn, up from $650m a year ago. The timing is the story. Days earlier, OpenAI and Anthropic each disclosed that their models had breached companies outside their intended scope. That is the anxiety Horizon3 is selling into. The company announced the round on Monday, billing it as the “AI vs. AI” era. If AI can now break in, its pitch runs, you should be the one turning it loose on your systems first. The round was co-led by returning backers NightDragon and NEA. NightDragon’s Dave DeWalt, who once ran FireEye and McAfee, is joining the board. Strategic investors include Singapore’s EDBI, the defence contractor SAIC and Qualcomm. That spread says the buyers are not confined to tech. Hor