TROJ_FAKEWIN.A

October 09, 2012
 Analysis by: Mark Joseph Manahan
 ALIASES:

TrojanDownloader:Win32/Karagany.L (Microsoft)

 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 executes then deletes itself afterward.

  TECHNICAL DETAILS

File Size:

74,240 bytes

File Type:

EXE

Initial Samples Received Date:

17 Aug 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 files:

  • %Application Data%\Microsoft\Windows\{random number}\{random filename}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It drops the following copies of itself into the affected system:

  • %Application Data%\Microsoft\Windows\{random number}\WindowsCodecExt.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It creates the following folders:

  • %Application Data%\Microsoft\Windows\{random number}
  • %Application Data%\Microsoft\VSComponents

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It executes then deletes itself afterward.

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
WindowsCodecExt = "%Application Data%\Microsoft\Windows\{random number}\WindowsCodecExt.exe"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}kybest40.in/image/makoto/price.php