I don't know if warden is checking checksum of some of the most known bots/helpers, but to be on a safe side it is very easy to change it and to have unique executable.
Let's take a example with notepad. You can train with it and if you like the results you can apply it to your bot.
First you need to open a command prompt (Start -> Run, type 'cmd')
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
C:\WINDOWS>copy notepad.exe notepad_test.exe
1 Datei(en) kopiert.
C:\WINDOWS>echo whatever_you_want >> notepad_test.exe
C:\WINDOWS>dir notepad*.exe
23.08.2001 14:00 67.072 NOTEPAD.EXE
14.11.2007 11:54 67.092 notepad_test.exe
start the notepad:
C:\WINDOWS>notepad_test.exe
It works! Good... Now go to your favorite bot, make a safe copy of a file, apply the changes and enjoy in better security. You have a boot that no one else in the world has.
Quick explanation: your executable knows where does it ends and it will never look after this point. You can have lots of garbage after and you can still use the program without any problems. I just put some random chars inside, but you can even paste complete file inside, it is up to you. Command for this would be:
C:\WINDOWS>type NOTEPAD.EXE >> notepad_test.exe
C:\WINDOWS>dir notepad*.exe
23.08.2001 14:00 67.072 NOTEPAD.EXE
14.11.2007 12:02 134.164 notepad_test.exe
It is definitely not the same file, but have the same function.
If you are interested in more details, or need more help just ask, I would be glad to help.