bgrab is a multi-threaded TCP banner grabbing script written in Python.
Currently only the Metasploit services CSV-output is supported:
msf > services -r tcp -c port -o services.out.txt
More specifically the script needs a file with the following syntax:
"127.0.0.1","1080"
"10.15.20.30","80"
...
Or anything like this:
127.0.0.1,8080
127.0.0.1,80
"gmail-smtp-in.l.google.com","25"
Invalid lines are ignored.