MalTrail is a malicious traffic detection system that maintains curated lists of known threats. This feed contains IP addresses of known mass-Internet scanners.

Mass scanners are hosts that continuously scan large portions of the Internet looking for vulnerable services. These include both research scanners (such as university projects) and malicious scanners looking for exploitation targets.

The list is maintained by stamparm, the same maintainer as the IPsum threat intelligence feeds. It is updated daily and contains IP addresses with inline annotations identifying the scanning organization or purpose where known.