Large-scale scanning
In the case of testing bigger organizations with multiple class B/C IP ranges, large-scale scanning is engaged. For example, with a global company, often, a number of IP blocks exist as part of external internet facing. As mentioned earlier in Chapter 2, Open-Source Intelligence and Passive Reconnaissance, attackers do not have time limitations to scan, but penetration testers do. Pentesters can engage multiple tools to perform the activity; Masscan is one such tool that would be engaged to scan large-scale IP blocks to quickly analyze the live hosts in the target network. Masscan is installed in Kali by default.
The biggest advantage of Masscan is the randomization of hosts, ports, speed, flexibility, and compatibility. Figure 3.22 provides a Class C scanning network within a few seconds to complete and identify the available HTTP service on port 80 and services running on the target hosts:
