TROJ_SCAR.VTG


 ALIASES:

ERROR (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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:

2,956,800 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

26 Apr 2012

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 Root%\Windupdt\winupdate.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It creates the following folders:

  • %System Root%\Windupdt

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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\Run
winupdater = "%System Root%\Windupdt\winupdate.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
UserInit = "%System%\userinit.exe,%System Root%\Windupdt\winupdate.exe"

(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)

Other System Modifications

This Trojan deletes the following files:

  • %Windows%\Addresses.TMP
  • %Windows%\Memory.TMP

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Enigma Protector\
28B621751F49F654-09F33A2659E7B90A\3842CAC48223B9A0-9A50CC0D9B84756F

HKEY_CURRENT_USER\Software\DC3_FEXEC

HKEY_CURRENT_USER\Software\sang sinsang

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Enigma Protector\
28B621751F49F654-09F33A2659E7B90A\3842CAC48223B9A0-9A50CC0D9B84756F
6CCFFA97 = "{random values}"

HKEY_CURRENT_USER\Software\sang sinsang
Undo = "1"

HKEY_CURRENT_USER\Software\sang sinsang
Advanced = "1"

HKEY_CURRENT_USER\Software\sang sinsang
SeperateThread = "1"

HKEY_CURRENT_USER\Software\sang sinsang
Use hyp27scan if posible = "0"

HKEY_CURRENT_USER\Software\sang sinsang
ScanThreadpriority = "4"

HKEY_CURRENT_USER\Software\sang sinsang
First Time User = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = "0"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wscsvc
Start = "4"

(Note: The default value data of the said registry entry is 2.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and delete files detected as TROJ_SCAR.VTG using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Enigma Protector\28B621751F49F654-09F33A2659E7B90A
    • 3842CAC48223B9A0-9A50CC0D9B84756F
  • In HKEY_CURRENT_USER\Software
    • DC3_FEXEC
  • In HKEY_CURRENT_USER\Software
    • sang sinsang
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies
    • System

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • winupdater = "%System Root%\Windupdt\winupdate.exe"
  • In HKEY_CURRENT_USER\Software\Enigma Protector\28B621751F49F654-09F33A2659E7B90A\3842CAC48223B9A0-9A50CC0D9B84756F
    • 6CCFFA97 = "{random values}"
  • In HKEY_CURRENT_USER\Software\sang sinsang
    • Undo = "1"
  • In HKEY_CURRENT_USER\Software\sang sinsang
    • Advanced = "1"
  • In HKEY_CURRENT_USER\Software\sang sinsang
    • SeperateThread = "1"
  • In HKEY_CURRENT_USER\Software\sang sinsang
    • Use hyp27scan if posible = "0"
  • In HKEY_CURRENT_USER\Software\sang sinsang
    • ScanThreadpriority = "4"
  • In HKEY_CURRENT_USER\Software\sang sinsang
    • First Time User = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • EnableFirewall = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DisableNotifications = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • EnableLUA = "0"

Step 5

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wscsvc
    • From: Start = "4"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: UserInit = "%System%\userinit.exe,%System Root%\Windupdt\winupdate.exe"
      To: UserInit = ""%Windows%\system32\userinit.exe,""

Step 6

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\Windupdt

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_SCAR.VTG. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Windows%\Addresses.TMP
  • %Windows%\Memory.TMP


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