Symbian worm sighted in the wild

Malware pretends to be media or image file.

A new worm has been sighted in the wild that operates on the

Symbian

operating system, which is used on many mobile phones. The worm, which researchers at

F-Secure

have called SymbOS/Beselo, shares many similarities with the SymbOS/Commwarrior worm that was first seen

nearly three years ago

and affects phones that use the

S60

2nd Edition platform, which is used on many

Nokia

phones. It is believed not to work on 3rd Edition phones.

Infected devices will receive a file that pretends to be either a media file (

sex.mp3

or

love.rm

) or an image file (

beauty.jpg

). However, unlike

Windows

, files on

Symbian

are recognised by their file types rather than by their extension and all three files are in fact

.sis

application files. When a user tries to open such a file, the malware will attempt to install itself. Users will still have to accept the installation for the worm to become active, but it is known that many will automatically click ‘yes’.

Once active, the worm will try to spread itself both by sending itself in MMS messages and by using Bluetooth. Moreover, it will try to spread to generated numbers as well. All these numbers are based in China and belong to the same mobile operator. Some of the numbers have been verified as belonging to real people, rather than being premium numbers. Security researchers are still investigating what the malware tries to achieve this way.

Users are advised to think carefully before clicking ‘yes’ when asked whether they want to install an application on their phone. Moreover, they should be aware that opening a media or image file does not require the installation of a new application.

More can be found at

F-Secure


here

and at

Fortinet


here

.

Posted on 23 January 2008 by

Virus Bulletin