Files detected as JS/forcepopup@troj are attempting to install software that generates popup windows. The software is capable of bypassing popup blockers such as Internet Explorer popup blocker, Norton Internet Security popup blocker, and Google Toolbar. Furthermore, it has a tracking cookie that can be used to track the affected user's browsing habits.
Allow F-Secure Anti-Virus to disinfect the relevant files.
For more general information on disinfection, please see Removal Instructions.