ALIAS:

SymbOS/Bootton.C

Bootton.C is a SIS file that installs small component that resets the device if executed, this component is installed into locations where it replaces system and third party applications. Bootton.C installs also Doomboot.A components that cause reboot to fail. Thus leaving phone in unusable state. In some cases installation fails but still some components of the malware are installed into the phone.

In its structure Bootton.C is quite similar to Skulls family trojans. With the exception that instead of replacing system files with corrupted binaries,the Bootton.C uses application that causes device to reboot.

In the device that is infected with Bootton.C, pressing menu button or any system application button the device immediately reboots. Installed Doomboot.A components cause reboot to fail. Thus leaving phone in unusable after reboot state.

Bootton.C disables most of critical system functions and third party file managers, so that even if the device wouldn't immediately reboot it is still unusable before it is disinfected.

In addition of disabling applications on the phone, the Bootton.C also installs modified Cabir that SymbOS/Onehop.A uses to distribute Bootton.C. But this file does not get executed automatically, and even if started by user is unable to send anything as the file it is trying to send does not exist on the system.

If Bootton.C is installed only the calling from the phone and answering calls works. All functions which need some system application, such as SMS and MMS messaging, web browsing and camera no longer function.

Detection

Generic detection that detects Bootton.B was published for F-Secure Mobile Anti-Virus on November 19th, 2004 in database build number 11.

Write-up:Mika Tolvanen December 7th, 2005;