If you want to know what version of Linux you're using look at the file /etc/issue
As for what's being run when you log in there'll be shell configuration files and it's possible there's something being called in the PAM stack. Shell files will depend on what shell you're using and the version of Linux. The shell is probably bash. You can tell by typing
If it's bash, then look at files like /etc/bash* and /etc/*profile to see if you can find a command that might be casing the message and delay.
See if you can recreate the problem message and delay by invoking a new instance of the shell. For example if you're using bash then type
If that does create the message and delay then type
to exit that instance of the shell. Then try running
and you'll see what's being accessed/run. If the output goes past too quick then you can use the strace -o option to send the output to a file. Also using -t might be useful as it puts the time at the start of each line, which will help when you're trying to find the point in the file when the delay is happening.
$ strace -o straceoutput -t bash
To see if there's anything being called from the PAM stack look at the files which are probably in /etc/pam.d