F-Secure Virus Descriptions : Wdialupd

NAME:	Wdialupd
ALIAS:	W32/Wdialupd.Adware, PornDial-177, Dialer.Porno.J,
ALIAS:	TROJ_WDIALUPD.A, Trojan.Win32.Dialer, Dialer

TECHNICAL INFORMATION

We have received several reports about this adware/downloader. The messages that the adware was distributed in, appear to have certain common characteristics. 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: Ero Carrera, Alexey Podrezov; F-Secure Corp.; May 26th-June 9th, 2003]