TROJ_TRACUR.BH

October 09, 2012
 Analysis by: Sabrina Lei Sioting
 Modified 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: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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:

349,184 bytes

File Type:

DLL

Memory Resident:

No

Initial Samples Received Date:

26 Jul 2011

Payload:

Monitors browser activities, Drops files, Creates files

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 component file(s):

  • %Application Data%\Google\Chrome\User Data\Default\Default\{random foldername}\contentscript.js detected as JS_TRACUR.BH
  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}\chrome\xulcache.jar - detected as JS_TRACUR.BH

(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.)

It then creates the following non-malicious file(s):

  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}\chrome.manifest
  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}\defaults\preferences\xulcache.js
  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}\install.rdf
  • %Application Data%\Google\Chrome\User Data\Default\Default\{random foldername}\manifest.json

(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.. %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:

  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}
  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}\chrome
  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}\defaults
  • %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}\defaults\preferences
  • %Application Data%\Google\Chrome\User Data\Default\Default\{random foldername}

(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.. %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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Global\Mutex_csjkpuoiqd

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CLASSES_ROOT\CLSID\{random CLSID}\
InprocServer32
{default} = "{malware path}\{malware name}.dll"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{05D357D0-8972-4AA9-83A6-150BF5C12851}\InprocServer32
{default} = "{malware path}\{malware name}.dll"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{random CLSID}

NOTES:
This trojan monitors the system's browsing activities and may redirect the page to a malicious URL when one of the following sites are visited:

  • alltheweb.com
  • altavista.com
  • ask.com
  • bing.com
  • gigablast.com
  • google.
  • hotbot.com
  • search.aol.com
  • search.lycos.com
  • search.netscape.com
  • search.yahoo.com
  • snap.com
  • youtube.com/results
  • vimeo.
  • facebook.
  • tube.
  • myspace.
  • wikipedia.

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

8.310.12

FIRST VSAPI PATTERN DATE:

26 Jul 2011

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_TRACUR.BH

Step 3

Remove malware/grayware files dropped/downloaded by TROJ_TRACUR.BH

    • JS_TRACUR.BH

Step 4

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects
    • {random CLSID}

Step 5

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_CLASSES_ROOT\CLSID\{random CLSID}\InprocServer32
    • {default} = {malware path}\{malware name}.dll
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{05D357D0-8972-4AA9-83A6-150BF5C12851}\InprocServer32
    • {default} = {malware path}\{malware name}.dll

Step 6

Search and delete these folders

[ 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\Mozilla\Firefox\Profiles\{random characters}.default\extensions\{random CLSID for Firefox}
%Application Data%\Google\Chrome\User Data\Default\Default\{random foldername}

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_TRACUR.BH. 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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