TROJ_DLOADER.UQY

 Analysis by: Jed Valderama

 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. It may be downloaded from remote sites by other malware.

This file contains a URL where it connects to possibly download other files. It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

97,792 bytes

Initial Samples Received Date:

12 Jul 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.

It may be downloaded from remote site(s) by the following malware:

  • JAVA_BLACOLE.EV

Installation

This Trojan drops the following copies of itself into the affected system:

  • %System%\V3LiveRun.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
AhnLab V3Lite Update Process = "%System%\V3LiveRun.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\Help
Help Version = "{Random}"

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKLM\Software\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = "ws2help.dll"

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

Other Details

This file contains a URL where it connects to possibly download other files. As of this writing, this file contains the following URLs:

  • sourceforge.net/users/{BLOCKED}511
  • {BLOCKED}is.co.kr/h.gif

It deletes itself after execution.

NOTES:

This Trojan modifies the following file by adding an export function:

  • %System%\ws2help.dll

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.252.04

FIRST VSAPI PATTERN DATE:

12 Jul 2012

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

Scan your computer with your Trend Micro product and note files detected as TROJ_DLOADER.UQY

Step 3

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_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • AhnLab V3Lite Update Process = "%System%\V3LiveRun.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Help
    • Help Version = "{Random}"

Step 4

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\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • From: AppInit_DLLs = "ws2help.dll"
      To: AppInit_DLLs = ""

Step 5

Search and delete the file detected as TROJ_DLOADER.UQY

*Note: Some component files may be hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.

To manually delete a malware/grayware file from the affected system:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADER.UQY. 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.


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