TROJ_DLDR.CD

 Analysis by: Nikko Tamana

 ALIASES:

Trojan:Win32/Busky.D (Microsoft), Downloader.Affiliase (Norton)

 PLATFORM:

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

 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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

186,368 bytes

File Type:

DLL

Initial Samples Received Date:

08 Apr 2009

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 file(s)/component(s):

  • %Windows%\PerfInfo\NAnWpqHSC3wp.exe.bak
  • %Windows%\shngbggq\1.png
  • %Windows%\shngbggq\2.png
  • %Windows%\shngbggq\3.png
  • %Windows%\shngbggq\4.png
  • %Windows%\shngbggq\5.png
  • %Windows%\shngbggq\6.png
  • %Windows%\shngbggq\7.png
  • %Windows%\shngbggq\8.png
  • %Windows%\shngbggq\9.png
  • %Windows%\shngbggq\bottom-rc.gif
  • %Windows%\shngbggq\config.png
  • %Windows%\shngbggq\content.png
  • %Windows%\shngbggq\download.gif
  • %Windows%\shngbggq\frame-bg.gif
  • %Windows%\shngbggq\frame-bottom-left.gif
  • %Windows%\shngbggq\frame-h1bg.gif
  • %Windows%\shngbggq\head.png
  • %Windows%\shngbggq\icon.png
  • %Windows%\shngbggq\indexwp.html
  • %Windows%\shngbggq\main.css
  • %Windows%\shngbggq\memory-prots.png
  • %Windows%\shngbggq\net.png
  • %Windows%\shngbggq\pc-mag.gif
  • %Windows%\shngbggq\pc.gif
  • %Windows%\shngbggq\poloska1.png
  • %Windows%\shngbggq\poloska2.png
  • %Windows%\shngbggq\poloska3.png
  • %Windows%\shngbggq\promowp1.html
  • %Windows%\shngbggq\promowp2.html
  • %Windows%\shngbggq\promowp3.html
  • %Windows%\shngbggq\promowp4.html
  • %Windows%\shngbggq\promowp5.html
  • %Windows%\shngbggq\reg.png
  • %Windows%\shngbggq\repair.png
  • %Windows%\shngbggq\scr-1.png
  • %Windows%\shngbggq\scr-2.png
  • %Windows%\shngbggq\start.png
  • %Windows%\shngbggq\styles.css
  • %Windows%\shngbggq\Thumbs.db
  • %Windows%\shngbggq\top-rc.gif
  • %Windows%\shngbggq\vline.gif
  • %Windows%\shngbggq\wp.png

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

It creates the following folders:

  • %Windows%\PerfInfo
  • %Windows%\shngbggq

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

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\policies\
Explorer\Run
{random characters} = "rundll32.exe "{Malware Path and File Name}.dll",DllCleanServer"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Preinstall

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run

It adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Preinstall
btsc = "{hex values}"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.24.246/hash?url=http:%2F%2Fwinxpspeedup.com%2Fdemo%2Fwinspeedup_full_installer.exe&hid=none&b=0&e=0000ffff

However, as of this writing, the said sites are inaccessible.