Analysis by: Kiyoshi Obuchi
ALIASES:

Trojan:Win32/Gandcrab.AF (Microsoft); W32/Kryptik.GJYS!tr (Fortinet)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Ransomware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

Tamaño del archivo 999,424 bytes
Tipo de archivo EXE
Fecha de recepción de las muestras iniciales 21 Aug 2018

Arrival Details

This Ransomware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Ransomware drops the following copies of itself into the affected system:

  • %ProgramData%\WrdJdgYRmg\winsrvc32.exe

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData in Windows Vista, 7, and 8.)

It drops the following files:

  • %ProgramData%\WrdJdgYRmg\cfgi
  • %ProgramData%\WrdJdgYRmg\cfg

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData in Windows Vista, 7, and 8.)

It adds the following processes:

  • %System%wuapp.exe -c "%Program Data%\WrdJdgYRmg\cfg"

It creates the following folders:

  • %ProgramData%\WrdJdgYRmg

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData in Windows Vista, 7, and 8.)

Autostart Technique

This Ransomware drops the following file(s) in the Windows Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\BfWTjSzBAA.url

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows XP, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Other Details

This Ransomware connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.197.60/new.txt

However, as of this writing, the said sites are inaccessible.