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.
Depending on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the suspect file, or ask you for a desired action.
More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.
You may also refer to the Knowledge Base on the F-Secure Community site for more information.