Adware:W32/WhenU displays targeted advertisements during the web browsing session.
During installation, a unique machine ID is generated to track the number of installations.
If the program is installed as part of a bundled package, an affiliate ID is also generated to indicate the product the program was bundled with. In the communication with WhenU servers, the affiliate ID is included and the unique machine ID excluded.
In order to target advertisements to appropriate viewers, the program monitors the user's browsing behavior. Details monitored include visited URLs, search terms entered and content of webpages viewed.
Unlike most adware, WhenU does not forward collected data to its servers for analysis. Instead, the analysis and content selection is performed on the local system, as the program uses the collected browsing information to query a local database and chose the most appropriate advertisement to display.
Once selected, a request is send to the remote server to download the selected content. The reason for the selection is included in the request. In addition, if the user subsequently clicks on the advertisement, the action is reported back to the server.
The program has several related programs, all based on the same technology. The three most common are:
WhenU's SearchBar is a toolbar hooked on to the Desktop that displays contextual advertisements in the form of rotating text links accessible from within the application. Performing search queries via the SearchBar produces search results that are monitored by the search provider.
WhenU's SaveNow displays popup advertisements during the web browsing session. The advertisements usually relate to discount offers. The program runs in the background, with a small tray icon visible.
Save behaves exactly like SaveNow, but is usually bundled with free software to generate profit for the free software vendor.