TROJ_DLOADER.LLC

April 24, 2013
 ALIASES:

Trojan:Win32/SystemHijack.gen!C (Microsoft); Downloader (Symantec); Trojan-Downloader.Win32.Delf.aet (Kaspersky); Packer.NSAnti.Gen (v) (Sunbelt); May be infected by unknown virus Win32/DH{A2c2O1BPFVEcUyVXTg} (AVG)

 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:

9,797 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

24 Apr 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%\ssopure.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_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{63E16148-3A71-99D9-2524-FE3574645AFF}
StubPath = "%System%\ssopure.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{63E16148-3A71-99D9-2524-FE3574645AFF}

It deletes the following registry keys:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Active Setup\Installed Components\{63E16148-3A71-99D9-2524-FE3574645AFF}

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}r.cn/muma/0.exe
  • http://www.{BLOCKED}r.cn/muma/1.exe
  • http://www.{BLOCKED}r.cn/muma/2.exe
  • http://www.{BLOCKED}r.cn/muma/3.exe
  • http://www.{BLOCKED}r.cn/muma/4.exe
  • http://www.{BLOCKED}r.cn/muma/5.exe
  • http://www.{BLOCKED}r.cn/muma/6.exe
  • http://www.{BLOCKED}r.cn/muma/7.exe
  • http://www.{BLOCKED}r.cn/muma/8.exe
  • http://www.{BLOCKED}r.cn/muma/9.exe
  • http://www.{BLOCKED}r.cn/muma/10.exe
  • http://www.{BLOCKED}r.cn/muma/11.exe
  • http://www.{BLOCKED}r.cn/muma/12.exe
  • http://www.{BLOCKED}r.cn/gx.exe

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {63E16148-3A71-99D9-2524-FE3574645AFF}

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{63E16148-3A71-99D9-2524-FE3574645AFF}
    • StubPath = "%System%\ssopure.exe"

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DLOADER.LLC. 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 6

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {63E16148-3A71-99D9-2524-FE3574645AFF}


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