Analysis by: Joachim Suico
ALIASES:

Downloader.Ponik (Symantec); W32/FrauDrop.AD!tr (Fortinet); Trojan-Dropper.Win32.FrauDrop.aijhq (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

  TECHNICAL DETAILS

File Size: 966,299 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 29 Apr 2015

Arrival Details

This Trojan 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 Trojan drops the following files:

  • %User Temp%\15_01_2015.doc
  • %User Temp%\vnc\MSRC4Plugin_for_sc.dsm
  • %User Temp%\vnc\rc4.key
  • %User Temp%\vnc\UltraVNC.ini
  • %User Temp%\vnc\winlogons.exe
  • %User Temp%\vnc\cop\MSRC4Plugin_for_sc.dsm
  • %User Temp%\vnc\cop\rc4.key
  • %User Temp%\vnc\cop\UltraVNC.ini
  • %User Temp%\vnc\cop\win.exe
  • %User Temp%\vnc\cop\winlogons.cmd
  • %User Temp%\vnc\cop\winlogons.exe
  • %User Temp%\vnc\cop\winlogons.vbs
  • %Windows%\Tasks\ChromeUpdates_ups.job

(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.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It drops the following non-malicious file:

  • %User Temp%\wget.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 creates the following folders:

  • %Application Data%\ChromeUpdates
  • %User Temp%\vnc
  • %User Temp%\vnc\cop
  • %Windows%\ChromeUpdates

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %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.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Download Routine

This Trojan accesses the following websites to download files:

  • http://e.{BLOCKED}j.ua/dumper/backup/chrome-xvnc-v5517.exe
  • http://e.{BLOCKED}j.ua/dumper/backup/chromeupdates.exe

It saves the files it downloads using the following names:

  • %Application Data%\chromeupdates.exe
  • %User Temp%\chrome-xvnc-v5517.exe
  • %User Temp%\chromeupdates.exe
  • %Windows%\ChromeUpdates\chromeupdates.exe
  • %User Startup%\chrome-xvnc-v5517.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %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.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • grom56.{BLOCKED}s.net:5500