A multicomponent rootkit that can infect both 32-bit and 64-bit versions of Windows. The installation process is initiated by a
shellcode created using a special method (Return-oriented
programming) and executed in explorer.exe. At that, Trojan.Gapz.1 employs undocumented features implemented in the interface event handler.
Moreover, the bootkit's installer attempts to bypass UAC by exploiting two vulnerabilities—the first one is related to incorrect processing
of a registry key when the EnableEUDC feature is executed, and the second one is a vulnerability in the graphics subsystem (when using the specially crafted Dexter
Trojan.Gapz.1 analyzes the hard drive structure of the infected computer, initializes the system partition, generates a special binary image and places it to reserved partitions. After that, the Trojan modifies only one field in the BOOT sector forcing the system loader
to download and execute the malicious code. At that, MBR (Master Boot Record) remains unchanged.
Trojan.Gapz.1 is a kernel of a multicomponent malicious program whose main purpose is to create a suitable environment to download other malicious components contained in the binary image loaded from the disk. These modules are implemented as blocks of assembled code that, when executed, interacts with the rootkit's API.
If the operating system (OS) can be loaded (either normally or in safe mode), download Dr.Web Security Space and run a full scan of your computer and removable media you use. More about Dr.Web Security Space.
If you cannot boot the OS, change the BIOS settings to boot your system from a CD or USB drive. Download the image of the emergency system repair disk Dr.Web® LiveDisk , mount it on a USB drive or burn it to a CD/DVD. After booting up with this media, run a full scan and cure all the detected threats.
If the mobile device is operating normally, download and install Dr.Web for Android. Run a full system scan and follow recommendations to neutralize the detected threats.
If the mobile device has been locked by Android.Locker ransomware (the message on the screen tells you that you have broken some law or demands a set ransom amount; or you will see some other announcement that prevents you from using the handheld normally), do the following:
Load your smartphone or tablet in the safe mode (depending on the operating system version and specifications of the particular mobile device involved, this procedure can be performed in various ways; seek clarification from the user guide that was shipped with the device, or contact its manufacturer);
Once you have activated safe mode, install the Dr.Web for Android onto the infected handheld and run a full scan of the system; follow the steps recommended for neutralizing the threats that have been detected;