WORM_FUJACKS.HV

November 03, 2012
 ALIASES:

Worm:Win32/Emerleox.gen!A (Microsoft); W32/Fujacks.worm (McAfee); W32.Fujacks!gen (Symantec); Win32.Fujacks.Gen (v) (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This worm 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:

32,768 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Nov 2012

Arrival Details

This worm 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 worm drops the following copies of itself into the affected system:

  • %System%\drivers\svchast.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
svcshare = "%System%\drivers\svchast.exe"

Other System Modifications

This worm modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"

(Note: The default value data of the said registry entry is 1.)

Dropping Routine

This worm drops the following files:

  • %Program Files%\Desktop_.ini
  • %Program Files%\Adobe\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Esl\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Desktop_.ini
  • %System Root%\autorun.inf
  • %Program Files%\Adobe\Reader 10.0\Reader\AIR\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Browser\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\IDTemplates\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\IDTemplates\ENU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Javascripts\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Legal\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Legal\ENU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\AcroForm\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\AcroForm\PMP\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Annotations\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Annotations\Stamps\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Annotations\Stamps\ENU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Multimedia\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Multimedia\MPP\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins3d\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins3d\prc\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Services\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\SPPlugins\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Tracker\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\CMap\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Font\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Font\PFM\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\LanguageNames2\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Providers\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Providers\Proximity\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Providers\Proximity\11.00\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\SaslPrep\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\ICU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\Adobe\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\Mac\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\win\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Setup Files\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Setup Files\{AC76BA86-7AD7-1033-7B44-AA0000000001}\Desktop_.ini
  • %Program Files%\Microsoft.NET\Desktop_.ini
  • %Program Files%\Microsoft.NET\RedistList\Desktop_.ini
  • %Program Files%\MSBuild\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Windows Workflow Foundation\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Windows Workflow Foundation\v3.0\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Windows Workflow Foundation\v3.5\Desktop_.ini
  • %Program Files%\MSN Gaming Zone\Desktop_.ini
  • %Program Files%\MSXML 6.0\Desktop_.ini
  • %Program Files%\MSXML 6.0\EULA\Desktop_.ini
  • %Program Files%\Online Services\Desktop_.ini
  • %Program Files%\Reference Assemblies\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.0\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.0\RedistList\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.5\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.5\RedistList\Desktop_.ini
  • %Program Files%\Uninstall Information\Desktop_.ini
  • %Program Files%\WinPcap\Desktop_.ini
  • %Program Files%\xerox\Desktop_.ini
  • %Program Files%\xerox\nwwia\Desktop_.ini
  • %System Root%\GH0ST.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other Details

This worm connects to the following possibly malicious URL:

  • http://www.{BLOCKED}azy.com/ad/test/1.txt

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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
    • svcshare = "%System%\drivers\svchast.exe"

Step 4

Restore this modified 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\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • From: CheckedValue = "0"
      To: CheckedValue = ""1""

Step 5

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.
  • %Program Files%\Desktop_.ini
  • %Program Files%\Adobe\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Esl\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Desktop_.ini
  • %System Root%\autorun.inf
  • %Program Files%\Adobe\Reader 10.0\Reader\AIR\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Browser\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\IDTemplates\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\IDTemplates\ENU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Javascripts\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Legal\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Legal\ENU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\AcroForm\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\AcroForm\PMP\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Annotations\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Annotations\Stamps\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Annotations\Stamps\ENU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Multimedia\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins\Multimedia\MPP\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins3d\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\plug_ins3d\prc\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Services\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\SPPlugins\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Reader\Tracker\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\CMap\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Font\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Font\PFM\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\LanguageNames2\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Providers\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Providers\Proximity\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\Linguistics\Providers\Proximity\11.00\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\SaslPrep\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\ICU\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\Adobe\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\Mac\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Resource\TypeSupport\Unicode\Mappings\win\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Setup Files\Desktop_.ini
  • %Program Files%\Adobe\Reader 10.0\Setup Files\{AC76BA86-7AD7-1033-7B44-AA0000000001}\Desktop_.ini
  • %Program Files%\Microsoft.NET\Desktop_.ini
  • %Program Files%\Microsoft.NET\RedistList\Desktop_.ini
  • %Program Files%\MSBuild\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Windows Workflow Foundation\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Windows Workflow Foundation\v3.0\Desktop_.ini
  • %Program Files%\MSBuild\Microsoft\Windows Workflow Foundation\v3.5\Desktop_.ini
  • %Program Files%\MSN Gaming Zone\Desktop_.ini
  • %Program Files%\MSXML 6.0\Desktop_.ini
  • %Program Files%\MSXML 6.0\EULA\Desktop_.ini
  • %Program Files%\Online Services\Desktop_.ini
  • %Program Files%\Reference Assemblies\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.0\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.0\RedistList\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.5\Desktop_.ini
  • %Program Files%\Reference Assemblies\Microsoft\Framework\v3.5\RedistList\Desktop_.ini
  • %Program Files%\Uninstall Information\Desktop_.ini
  • %Program Files%\WinPcap\Desktop_.ini
  • %Program Files%\xerox\Desktop_.ini
  • %Program Files%\xerox\nwwia\Desktop_.ini
  • %System Root%\GH0ST.exe

Step 6

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


Did this description help? Tell us how we did.