user40, you have to go into a ranked match and kill people THEN the weapon attachments are unlocked, same thing with power/armor/stealth modules...they get upgraded.
Sad thing is, you might be able to get one match in then you get kicked and reset. Hell I am using MP cracked and i got reset.
I recommend picking your favorite gun, or guns, get into a rather long match, use your weapons and modules, get them up. And leave as quick as possible...as to not lose your things, and then delete the scripts so they aren't detected in another match.