GreyNoise operates a global network of sensors that collect and analyze internet background noise to help security teams distinguish between targeted attacks and opportunistic scanning activity. The platform deploys sensors across different network locations to observe and categorize traffic hitting internet-facing systems, tagging IP addresses based on their behavior patterns. GreyNoise provides threat intelligence through API-accessible data, real-time blocklists, and a visualization platform that allows security practitioners to investigate IP addresses, understand their historical behavior, and identify malicious activity. The company's detection rules categorize traffic as benign, malicious, or unknown, with tags identifying specific attack types such as RDP crawlers, SMB exploits, and vulnerability scanners. Their product offerings include IP similarity searches to hunt for related bad actors, IP timeline views showing behavioral changes over time, and GreyNoise Block for configurable blocklists. The service helps organizations filter out mass internet scanning noise from security alerts, allowing teams to focus on genuine threats rather than opportunistic automated attacks that target all internet-connected systems indiscriminately.