runZero

runZero, founded in 2019 in Austin, Texas as Rumble Network Discovery before rebranding in August 2022, solves a problem most attack surface tools only partly address: finding the assets an organization does not already know it has. Its scanner fingerprints devices across IT, OT, IoT, cloud, and mobile without requiring agents or credentials, running from a lightweight command-line binary on Windows, macOS, and multiple Linux architectures — down to hardware as small as a Raspberry Pi — while the management layer runs in the cloud or on-premises.

The company was founded by HD Moore, the creator of the Metasploit penetration testing framework, which gives runZero a level of technical credibility in the security research community that most asset-discovery vendors don’t carry. That pedigree shows up in the product’s positioning: rather than relying on a CMDB or endpoint agent (both of which only see what’s already been enrolled), runZero actively probes the network to surface shadow IT, forgotten OT/ICS equipment, and unmanaged IoT devices that create real, exploitable blind spots.

Commercially, runZero raised a $15 million Series A in March 2022 led by Decibel Partners and has grown to roughly 75 employees, with the platform now marketed around exposure management and attack path mapping in addition to core asset discovery. It has become a frequently cited reference point in security press coverage (Dark Reading, among others) of the asset-inventory and exposure-management category.

For CISOs, the practical value is straightforward: you cannot secure or patch what you don’t know exists, and runZero’s agentless approach means it can surface assets that agent-based and credentialed tools structurally cannot reach, including networks and OT segments where deploying agents isn’t feasible.