Masscan

Use masscan to asynchronously scan for open ports at incredible speeds, then later analyze the results with other tools

GitHub - robertdavidgraham/masscan: TCP port scanner, spews SYN packets asynchronously, scanning entire Internet in under 5 minutes.GitHub

Asynchronous high-speed TCP port scanner

Find open ports

The options masscan uses are very similar to nmap. It accepts a subnet or individual host as a target, and using the -p syntax you can provide a list, range or all ports using -p-. Then the output formats like -oX for XML or -oJ for JSON are useful when parsing the results with other tools afterwards.

Example

sudo masscan 192.168.1.0/24 -p- --rate 100000 -oX out.xml

Convert output to nmap format

Because masscan uses its own version of the XML output format, some tools won't work with this kind of output. To convert the masscan XML to nmap XML, we need to do two things:

1. Optionally: change the ownership from the output file from root to our current user

2. Remove the comment line <!-- masscan v1.0 scan -->

sudo chown $USER:$(id -gn) $1
sed -i '/<!-- masscan v1.0 scan -->/d' $1