If you type a command into the terminal, do you ever get something like: "I couldn't find that command...would you like to install it?" message? AFAIK that is where these mysterious processes come from. It sounds like a bug that has not been fixed (although I don't get them on my machine when I type in a command that is not installed).
In any case, that thread I linked to offered a solution:
You could try that out. I don't know if there are any side effects.Simple solution: rpm -e PackageKit-command-not-found and then log out and in (so bash forgets it too). Things start behaving themselves then, letting me make mistakes, and not trying to be too helpful.