VBS_DLOADR.YYSRC

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.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It connects to certain websites to send and receive information. It gathers information and reports it to its servers.

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 Startup%\{random}.vbs ← executes component files
• %User Profile%\chrome\{random}.vbs ← executes component files
• %User Profile%\{random}.bat ← executes century.dll
• %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\google chrome.lnk
• %Application Data%\Microsoft\Internet Explorer\Quick Launch\google chrome.lnk
• %Desktop%\google chrome.lnk
• %ProgramData%\Microsoft\Windows\Start Menu\Programs\google chrome.lnk
• %ProgramData%\Microsoft\Windows\Start Menu\Programs\Google Chrome\google chrome.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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:

• %User Profile%\ext ← extracted from ugt.zip

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other System Modifications

This Trojan deletes the following files:

• %User Profile%\ugt.zip
• %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\google chrome.lnk
• %Application Data%\Microsoft\Internet Explorer\Quick Launch\google chrome.lnk
• %Desktop%\google chrome.lnk
• %Desktop%\google chrome2.lnk
• %ProgramData%\Microsoft\Windows\Start Menu\Programs\google chrome.lnk
• %ProgramData%\Microsoft\Windows\Start Menu\Programs\Google Chrome\google chrome.lnk
• %All Users Profile%\Desktop\google chrome.lnk
• %All Users Profile%\Desktop\google chrome2.lnk
• %All Users Profile%\menu iniciar\programas\google chrome\google chrome.lnk
• %All Users Profile%\menu iniciar\programas\google chrome.lnk

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

• http://storage.{BLOCKED}apis.com/zeusthor/th006 ← ugt.zip
• http://storage.{BLOCKED}apis.com/zeusthor/d4 ← century.dll

It saves the files it downloads using the following names:

• %User Profile%\ugt.zip
• %User Profile%\myinside.dll ← extracted from ugt.zip
• %User Profile%\century.dll

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This Trojan connects to the following website to send and receive information:

• http://{BLOCKED}vx.net/log2.php

It does the following:

• It checks if the machines locale is set to Brazil.
• It deletes Google Chrome shortcuts and replace them with a shortcut that points to a component file.
• It drops the following files as markers:
  • %User Profile%\64x
  • %User Profile%\64bx
• It checks for the presence of the following files:
  • %Program Files%\gbplugin\gbiehuni.dll
  • %AppDataLocal%\aplicativo itau\itauaplicativo.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local 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 gathers the following information and reports it to its servers:

• System Caption
• OS Language
• Computer System Name
• Install Date
• Registered User
• Country Code
• System Version
• Architecture