I discovered this cookie on my computer (atdmt.com) recently. Norton Online would remove it but it kept showing up. I believe I successfully removed it by running a full system scan while my OS was booted in safe mode. This threat has been on my computer since before I began using Norton Online but now that this threat is gone how concerned should I be about changing all my passwords and other info on my computer. Norton says it is a low threat tracking cookie but I don't know what kind of information it collects. Does anyone know how serious this may have affected my computer?