TROJ_KULUOZ.BD

October 13, 2012
 ALIASES:

Trojan.Win32.Generic!BT (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:

48,640 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

11 Jun 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 creates the following folders:

  • %User Profile%\Application Data\529C50B4212C2CDD0B64EC3D2830AC72

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

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
qevdoebr = "%Application Data%\cduasjpg.exe"

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Version = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Name = "KWRELEFT.EXE"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Id = "KWRELEFT.EXE4FD2499B0005D000"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
MostRecentStart = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Name = "529C50B4212C2CDD0B64EC3D2830AC72.EXE"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Id = "529C50B4212C2CDD0B64EC3D2830AC72.EXE4FD2499B0005D000"

Dropping Routine

This Trojan drops the following files:

  • %Application Data%\kwreleft.exe
  • %User Profile%\529C50B4212C2CDD0B64EC3D2830AC72\529C50B4212C2CDD0B64EC3D2830AC72
  • %User Profile%\529C50B4212C2CDD0B64EC3D2830AC72\529C50B4212C2CDD0B64EC3D2830AC72.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.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}g.com/afyu/index.php?{random characters}
  • http://{BLOCKED}r.com/nygul/index.php?{random characters}
  • http://{BLOCKED}likeguarana.ru/forum/index.php?{random characters}
  • http://{BLOCKED}5.247.93/api/urls/?ts=cac22bfb&affid=41100
  • http://www.{BLOCKED}su.com/images/3.exe

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

Restart in Safe Mode

[ Learn More ]

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • qevdoebr = "%Application Data%\cduasjpg.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Version = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Name = "KWRELEFT.EXE"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Id = "KWRELEFT.EXE4FD2499B0005D000"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • MostRecentStart = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Name = "529C50B4212C2CDD0B64EC3D2830AC72.EXE"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Id = "529C50B4212C2CDD0B64EC3D2830AC72.EXE4FD2499B0005D000"

Step 4

Search and delete these files

[ Learn More ]
There may be some component files that are 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.
  • %Application Data%\kwreleft.exe
  • %User Profile%\529C50B4212C2CDD0B64EC3D2830AC72\529C50B4212C2CDD0B64EC3D2830AC72
  • %User Profile%\529C50B4212C2CDD0B64EC3D2830AC72\529C50B4212C2CDD0B64EC3D2830AC72.exe

Step 5

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.
  • %User Profile%\Application Data\529C50B4212C2CDD0B64EC3D2830AC72

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_KULUOZ.BD. 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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