Telnetlogger

This is a straightforward program designed to log login attempts made on Telnet, which operates on port 23.

As of October 23, 2016, infected Mirai machines across the globe are attempting to connect to Telnet on every IP address approximately once every minute.

This program logs both the IP addresses that are making the login attempts and the passwords they are using. I created it mainly because installing telnetd on a Raspberry Pi alone was not adequate.

The Mirai botnet does not accept the output from Telnet for some unknown reason, and it will not attempt to log in. Therefore, I needed to create something that would generate the type of Telnet output it expects. While developing this, I also wrote some code to parse the data and extract usernames and passwords. Usage: To see passwords and IP addresses displayed on stdout, simply run the program. Use the command: telnetlogger. If you want to log the information to files, you can use the -p and -i options like this: telnetlogger -p passwds.txt -i ips.txt. To listen on a different port for testing purposes, you can use the -l option: telnetlogger -l 2323. Be aware that on many systems, you may encounter an "access denied" error message because programs that open ports below 1024 require additional privileges. Therefore, you might need to run the program with sudo. Compiling: Use the command make or: