MGDropper.B is a minor variation of MGDropper.A trojan that was
found in December 2004.
MGDropper.B is a malicious SIS file dropper, that disables most
well known third party file managers and Anti-Virus software,
installs Cabir.X and drops MGDropper.A trojan.
The Cabir.X is started automatically when the MGDropper is installed
and will start spreading. When Cabir.X spreads from MGDropper
infected phone, the SIS files it sends will contain only the Cabir.X
not MGDropper.
MGDropper.B tries to disable F-Secure Mobile Anti-Virus by replacing it's
files with non-functional versions. However as F-Secure Mobile Anti-Virus
is capable of detecting Cabir.X contained by MGDropper using generic detection.
The Anti-Virus will detect the infected SIS file and prevent it from being
installed. Provided that the Anti-Virus is in realtime scan mode as it is
by default.
The Cabir.X worm dropped by MGDropper is already detected with generic
detection as Cabir.Xen. So the MGDropper is already detected and stopped
without need for updated Anti-Virus database.
Disinfection
Disinfection with two Series 60 phones
For full disinfection of MGDropper you need help of another Series 60 phone
that is not infected with the trojan, and clean memory card on that phone.
1. Install F-Skulls.sis into clean phones memory card with a clean phone
2. Put the memory card with F-Skulls into infected phone
3. Start up the infected phone, the application menu should work now
4. Go to application manager and uninstall the SIS file in which you installed the skulls variant
5. Download and install F-Secure Mobile Anti-Virus to remove any Cabirs dropped by the Skulls variant
http://www.europe.f-secure.com/estore/avmobile.shtml
or with mobile itself
http://mobile.f-secure.com
6. Install EFilemanager file manager application on your phone from http://www.psiloc.com
7. Insert the infected memory card into the phone and remove following files
E:\System\Apps\SystemExplorer\SystemExplorer.app
E:\System\Apps\smartfileman\smartfileman.app
E:\System\Apps\file\file.app
E:\System\Apps\Anti-Virus\Anti-Virus.app
E:\System\Apps\Anti-Virus\FsAVUpdater.app
E:\System\Apps\AppInst\Appinst.aif
E:\System\Apps\AppInst\Appinst.app
E:\System\Apps\cabirfix\cabirfix.app
E:\System\Apps\Decabir\DECABIR.APP
E:\System\Apps\Disinfect\Disinfect.app
E:\System\Apps\FExplorer\FExplorer.app
Detailed Description
Installation to system
When installed MGDropper will replace most common third party file managers,
Anti-Virus programs and application installer with non-functional versions.
Spreading in
MetalGear_by_scar69.sis
Payload
Drops MGDropper.A
Disables following applications
Simworks Anti-Virus
F-Secure Mobile Anti-Virus
Application installer
Cabirfix
Decabir
F-Cabir
FExplorer
File manager
Smart file manager
System Explorer
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