A loader for BackDoor.PlugX.38 written in C and designed to operate in 32-bit and 64-bit Microsoft Windows operating systems. It is an executable file that loads and decrypts the payload module.
The loader is an executable file and its original name is msvsct.exe. Its installation path on the infected system is C:\ProgramData\AppData\msvsct.exe. It writes itself to the registry autostart location: [HKCU\Software\Microsoft\Windows\CurrentVersion\Run] 'AUTORUN' = "c:\programdata\appdata\msvsct.exe.
The payload is located in msvsct.ini and is decrypted by the following script:
s = ''
for i in range(len(d)):
s += chr((((ord(d[i]) + 0x77) ^ 0x78) - 0x79) & 0xff)
After decryption the payload turns into shellcode, which loads the main malicious module as a dynamic link library (detected by Dr.Web as BackDoor.PlugX.38).
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;