W32.Gampxia is a worm that copies itself to removable media and shared folders. It also infects HTML files, which are detected as W32.Gampxia!html.

It downloads copies of Infostealer.Gampass, Hacktool, and WinPcap, a library used to monitor and capture network packets in Windows environments, onto the compromised computer.

More information can be found at this Symantec page.