I think you answered your own question, most likely a Norton 360 cleaning/scanning temporary file for various tasks, deleted at end of scan ? Good, no problem.
".tmp" are always temporary files created by anything. Usually safe to delete, unless the software stored information in transition, not written to proper place yet, such as deleting the files during installation of software, not recommended.
I have found certain or certain types of tmp files when doing social networking sites. Sometimes the connection gets really slow and there is bad lag. Cleaning the browsing history (temp files, history, cookies, etc) doesn't always work. It usually requires a complete process: 1. Delete browsing history, 2. log off, 3. repeat with a different program than the web-browser.
I have noticed most problems when there are certain web-pages that seem to be phishing or trying to obtain info about someone witht he "click me or click here" pop-ups, etc. Those hit the computer and slow down is immenient/a instant problem and only gets worse. Those are the same web-pages where you cannot shut down the browser or exit or close the winbdows, etc.
I am doubtful I have malware. I think I read on this site how to performa highly thorough scan when in safe mode, I'll look at that and do it in the short-term.
Just trying to understand the processes and figure out the way things work.
Usually a file name in a search engine produces the info about it.
First you can limit your browser cache memory usage, if you assigned more than 25% of your total RAM, it's too much. Second, java has an icon in your control panel (if installed properly) you can tell it what to do there. Adblock Plus is great, allows you to block popup frames that are scripted and bypass your normal popup blocker, use it wisely. Set all browsers and windows to use the same Temporary folder, then add this folder to CCleaner and it will pickup all garbage, instead of C:\windows\temp, C:\documents and settings\<username>(for you ALL and Default)\Local Settings\Temp, Temporary Internet Files, History, Recent Documents. Cleanup your startup tray (next to clock), Run Msconfig and remove anything that does not need to be loaded on startup and kept running. Tighten up your internet security, many sites will work with 3rd party cookies disabled and most will work with Session Only.
Your chat programs may default to saving logs of all text typed, not only is it a bad idea but a good source of bloating lag. Lastly, Never "Click Here" on any popups, especially if offering free downloads of a retail non-shareware software.