AttackSurfaceMapper (ASM) is a reconnaissance and attack surface discovery tool designed to automate the process of mapping potential targets within an organization's infrastructure. It combines open source intelligence (OSINT) with selective active reconnaissance techniques to expand and analyze a target’s external attack surface. Users can supply domains, subdomains, or IP addresses as input, and applies multiple discovery methods to identify additional related assets such as new subdomains, associated IP ranges, and hosts within the same network ownership. It performs both brute-force and passive enumeration techniques to uncover infrastructure components that may not be immediately visible. After building an expanded list of targets, AttackSurfaceMapper collects intelligence such as screenshots of web applications, information about exposed services, and possible vulnerabilities identified through integrated services. It can also search for publicly exposed credentials.