Analysis by: Nikko Tamana
ALIASES:

Generic.Ransom.Magniber.F8E5B4A7 (Bitdefender), a variant of Win32/Filecoder.Magniber.A trojan (NOD32)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:

  • 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.

It uses Windows Task Scheduler to create a scheduled task that executes the dropped copy. It executes then deletes itself afterward.

It is capable of encrypting files in the affected system.

It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 48,640 bytes
File Type: EXE
Initial Samples Received Date: 23 Oct 2017

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:

  • %User Temp%\fprgbk.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It adds the following processes:

  • "cmd.exe" /c "%System%\wbem\wmic shadowcopy delete"
  • %System%\eventvwr.exe
  • ping localhost -n 3
  • schtasks /create /SC MINUTE /MO 15 /tn fprgbk /TR pcalua.exe -a %User Temp%\fprgbk.exe
  • schtasks /create /SC MINUTE /MO 15 /tn {random alphanumeric characteristics} /TR %User Temp%\READ_ME_FOR_DECRYPT_{random alphanumeric characteristics}_.txt
  • pcalua.exe -a eventvwr.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It uses Windows Task Scheduler to create a scheduled task that executes the dropped copy.

It executes then deletes itself afterward.

Other Details

This Ransomware connects to the following possibly malicious URL:

  • http://{random alphanumeric characters}.orea{BLOCKED}.xyz
  • http://{random alphanumeric characters}.says{BLOCKED}.site
  • http://{random alphanumeric characters}.lock{BLOCKED}.party

It is capable of encrypting files in the affected system.

Ransomware Routine

This Ransomware appends the following extension to the file name of the encrypted files:

  • .fprgbk

It drops the following file(s) as ransom note:

  • {encrypted file path}\READ_ME_FOR_DECRYPT_{random alphanumeric characters}_.txt