We have received several reports about this adware/downloader. The messages that the adware was distributed in, appear to have certain common characteristics.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
The 'From:' field always consists of a seemingly random sequence of alphanumeric characters followed by '@yahoo.com'. In the reports we received the length of the alphanumeric string was not constant.
The 'Subject:' field looks like those from common SPAM (unsolicited e-mail), referring to porn and other miscellaneous topics.
In all the messages the attachment names are different, they can be the following:
action.zip adult_movies.zip my_videos.zip mymovie.zip yourfreemovie.zip
These ZIP files contain executables that are the actual installers/downloaders of the Wdialupd alware. The names of known Wdialupd executable files are:
1714.exe 2453.exe 2702.exe 5298.exe
When run, the Wdialupd asks a user to select his/her location and then attempts to download and activate additional components from Internet without asking for permission.
It posts information on the users location/language to the same address from where it tries to download files, nothing confidential appears to be posted.
The address is a hardcoded IP physically situated in Spain. At the time of this writing the address is unreachable.
The Wdialupd adware is detected by F-Secure Anti-Virus as:
Security risk or a "backdoor" program
because of its intrusiveness and because it appears to collect information about computer users.
It is advised to delete messages with Wdialupd downloaders and avoid running their executable files.
Description Created: Ero Carrera, Alexey Podrezov; F-Secure Corp.; May 26th-June 9th, 2003