TROJ_RANBYUS.AW

September 04, 2013
 Analysis by: Anthony Joe Melgarejo
 ALIASES:

TrojanSpy:Win32/Ranbyus.G (Microsoft)

 PLATFORM:

Windows 2000, Windows XP (32-bit and 64 bit), Windows Server 2003, Windows Vista (32-bit and 64 bit), Windows 7 (32-bit and 64 bit)

 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:

239,772 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Sep 2013

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 copies of itself into the affected system:

  • %System%\machineupdate32.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
Windows Debugger 32 = "%System%\machineupper32.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\{unreadable characters}

HKEY_CURRENT_USER\Software\BIFIT

HKEY_CURRENT_USER\Software\{unreadable characters}\
Z

HKEY_CURRENT_USER\Software\{unreadable characters}\
Z\Recent File List

HKEY_CURRENT_USER\Software\{unreadable characters}\
Z\Settings

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
SysDebug32 = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\svchost.exe = "%System%\svchost.exe:*:Enabled:Windows Debugger 32"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Hardware Profiles\Current\Software\
Microsoft\Windows\CurrentVersion\
Internet Settings
ProxyEnable = "0"

(Note: The default value data of the said registry entry is 1.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\SystemRestore

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}mo.com/profit_new2/index.php
  • http://{BLOCKED}o.com/ru_profit_new/index.php

NOTES:
It deletes the user's browser cookies.