Is it not likely that, if you're discussing FannieMae on phone, that you had previously searched for info on FannieMae on the net?? Your Index.Dat file would probably include that search info as well as several other places on your system. Sounds like you have some spyware. Possibly connected to some system or program updating operation. Example: Backweb collecting and sending daily to Logitech or HP under guise of checking for driver updates. Can happen silently in background any time you go on net.
I would download & run Ewido SS(free trial)

With these instructons(courtesy of Roddy32:


Dowload link http://www.ewido.net/en/


* Install ewido security suite
* When installing, under "Additional Options" uncheck "Install
background guard" and "Install scan via context menu".
* Launch ewido, there should be an icon on your desktop double-click it.
* The program will now go to the main screen

You will need to update ewido to the latest definition files.

* On the left hand side of the main screen click Update
* Then click on Start Update

The update will start and a progress bar will show the updates being
installed.
If you are having problems with the updater, you can use this link to
manually update ewido.
http://www.ewido.net/en/download/updates/

Once the updates are installed do the following:
* Click on scanner
* Click on Complete System Scan and the scan will begin.
* While the scan is in progress you will be prompted to clean files,
click OK
* When it asks if you want to clean the first file, put a check in the
lower left corner of the box that says "Perform action on all
infections" then choose clean and click OK.
* Once the scan has completed, there will be a button located on the
bottom of the screen named Save report
* Click Save report.
* Save the report .txt file to your desktop.

Now close ewido security suite.
Additionally I would run Updated Spybot & AdawareSE.
Plus I would get and use everyday CCleaner from 2 links in this post:
http://reviews.cnet.com/5208-7813-0.html?forumID=32&threadID=105074&messageID=1263885
One other thought: Do you have voice recognition software on machine w/ built in/or aux microphone that is left turned on when not in use? Just my 2 cents! Grin