Threat description


TYPEMonitoring Tool


Acallno.A is an SMS spying tool that runs on Symbian Series 60 Second Edition devices.

When Acallno.A is installed on the device it will forward all incoming and outgoing SMS messages to an external number that is specified within the software's configuration file. Acallno.A thus makes it possible for the individual that installs it to monitor all SMS traffic that the victim sends or receives on the target phone.

When active on the device, Acallno.A hides its process so that it is not visible in the Symbian process list. Also, it does not have an application icon and entry in the application uninstallation list. Therefore, the only way for a victim to detect Acallno.A is to locate the application files in file system or to use an antivirus application.

Acallno.A is limited by the unique IMEI code of the target device, so that a purchased copy of Acallno.A can only be installed to one specific device. The individual whom installs the spyware needs to know the IMEI code of the device beforehand.


Disinfecting using F-Secure Mobile Anti-Virus
  • Download F-Secure Mobile Anti-Virus and activate the Anti-Virus
  • Scan the phone and remove any components of the malware
  • Reboot the phone to remove memory resident components

Technical Details


When Acallno.A is installed the installation package will create following files to the device C: drive:

  • C:\System\apps\s60calls.exe
  • C:\System\apps\s60system.exe
  • C:\System\apps\s60system1.exe
  • C:\System\recogs\s60calls.mdl
  • C:\System\recogs\s60sysp.mdl
  • C:\System\recogs\s60syss.mdl
Hiding from the User

When Acallno.A is activated, it will remove its uninstallation information from the install logs and hide its process from application process list.

Also, Acallno.A does not have any kind of user interface or uninstallation option, so only way to detect its presence is to use antivirus or a third party file manager that shows the contents of System\apps directory.

Sending SMS Messages

Acallno.A monitors the users incoming and outgoing SMS traffic, and as soon as the user sends or receives an SMS message, Acallno.A will forward this to the number that is configured in the software licence.

To prevent the user from noticing the extra messages, Acallno.A will remove the message from the sent SMS messages list.

Description Created: 2006-08-29 11:09:26.0

Description Last Modified: Jarno Niemela, August 29, 2006; Sean Sullivan, August 29, 2006; Sean Sullivan, November 6, 2006

Description Details: Jarno Niemela, August 29, 2006

Technical Details: Jarno Niemela, August 29, 2006

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