What is it?
Quick Time Tray icon - qttask.exe

What does it do?
qttask.exe - This is is a task tray icon which is used as a shortcut to a number of QuickTime related features. You really don't need this in your system tray. It is safe to remove this from your startup. QuickTime's most common purpose is for watching movies commonly in the .mov format.

Virus Precautions:
You'll want to keep an eye on this google search for any known viruses. The normal location of qttask.exe is in your C:Program FilesQuickTimeqttask.exe At this time my search shows nothing that you need to worry about.