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F-Secure Trojan Information Pages : Cardtrap.AI

[ Summary ] | [ Disinfection ] | [ Detailed Description ] | [ Detection ]

Name:Cardtrap.AI
Type:Trojan
Category:Trojan
Platform:SymbOS
Date of Discovery:May 18, 2006

Summary

Cardtrap.AI is a Symbian SIS file trojan that disables several of Symbian's built-in applications, tries to damage some third party applications, and installs Windows malware to the memory card.

If you have installed Cardtrap.AI, the most important thing is to not reboot the phone and to follow the disinfection instructions in the section below.

Disinfection

Disinfection with two Series 60 phones

Use F-Skulls to allow for installation of F-Secure Mobile Anti-Virus
Install F-Secure Mobile Anti-Virus

Download F-Skulls tool from ftp://ftp.f-secure.com/anti-virus/tools/f-skulls.zip or directly to a clean phone from http://www.f-secure.com/tools/f-skulls.sis

  1. Install F-Skulls.sis onto the infected phone's memory card with a clean phone
  2. Put the memory card with the F-Skulls tool into the infected phone
  3. Start up the infected phone and the application installer should now work
  4. Go to the application manager and uninstall the SIS file in which you installed the malware
  5. Download F-Secure Mobile Anti-Virus from http://phoneav.com and activate the Anti-Virus
  6. Scan the phone and remove any remaining components of the malware
  7. Remove the F-Skulls tool with the application manager as the phone should now be clean
Disinfection for the cases when the phone is already rebooted and cannot start up

CAUTION! this method will remove all data on the device including calendar and phone numbers:

  1. Power off the phone
  2. Hold the following three buttons down - "answer call" + "*" + "3"
  3. Keep holding down the buttons and power on the phone
  4. Depending on the model, you will either get text that reads "formatting" or a start-up dialog that asks for the initial phone settings
  5. Your phone is now formatted and can be used again


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Detailed Description

Spreading in “Juggler® Theme Manager.sis”

Installation to the Phone
Cardtrap.AI tries to disable key system applications and third party products by installing several damaged files to the phone memory
.

Cardtrap.AI installs files from the following Symbian malware:

  • SymbOS/Doomboot.A

F-Secure Mobile Anti-Virus is capable of detecting Cardtrap.AI with generic detection, so if the phone has functional Anti-Virus installed Cardtrap.AI is blocked before it can be installed.

Installation to the MMC Card
Cardtrap.AI installs following Windows malware:

  • W32.Fourseman.B@mm
to the phone's MMC card. The malware is installed with a filename, icon, and shortcut link that tries to fool the user into clicking on them.


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Detection

F-Secure Mobile Anti-Virus for Symbian detects this malware starting from the update build number 28.


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Write-up: Mika Tolvanen, May 29, 2006

Technical Details: Mika Tolvanen, May 29, 2006

F-Secure Corporation