Kevin S. Killourhy Roy A. Maxion Toward Realistic and Artifact-Free Insider-Threat Data. 87-96 2007 ACSAC http://doi.ieeecomputersociety.org/10.1109/ACSAC.2007.49 conf/acsac/2007 db/conf/acsac/acsac2007.html#KillourhyM07