I wouldn't be so quick to try to delete the ntuser.dat.log, unless you're sure you have a problem. As a start, you might want to try scanning with A-Square's online scanner, to see if it compares with KL-Detector's results.
You might also try uploading the file to:
See if either of these threads shed some light:
I'm sure you'll get additional help..
A KL-Keylogger Said ntuser.dat.log is bad. What do you think? I could not delete this file. Should I be concerned?