Analysis by: Karl Dominguez

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via removable drives

It deletes files, which are related to other malware.

It is created to function as an Antivirus script that deletes suspicious files and restore commonly modified registry entries of malware.

This worm arrives via removable drives. It may be unknowingly downloaded by a user while visiting malicious websites.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size: 32,896 bytes
File Type: VBS
Memory Resident: Yes
Initial Samples Received Date: 02 Feb 2011

Arrival Details

This worm arrives via removable drives.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

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

  • %System%\FAantivirus.vbs

(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.)

It creates the following folders:

  • %Application Data%\dxdlls

(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.)

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = Fusion|Ace Enterprises

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = explorer.exe

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

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = %System%\userinit.exe, %System%\wscript.exe %System%\FAantivirus.vbs

(Note: The default value data of the said registry entry is %System%\userinit.exe,.)

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = 1

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
CurrentBuild = 1.511.1 () (Obsolete data - do not use)

(Note: The default value data of the said registry entry is {Operating System Dependent}.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion
ProductId = 55274-640-1011873-23573

(Note: The default value data of the said registry entry is {Operating System Dependent}.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = 0

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 0

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 0

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = http://www.socio.fusionace.com

(Note: The default value data of the said registry entry is {user-defined}.)

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Windows\System
DisableCMD = 0

(Note: The default value data of the said registry entry is 0.)

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • {drive letter}:\FAantivirus.vbs

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[autorun]
open=wscript.exe FAantivirus.vbs
icon=%systemroot%\System32\SHELL32.dll,8
action=Open folder to view files
shell\open=Open
shell\open\Command=wscript.exe FAantivirus.vbs
shell\Auto=AutoPlay
shell\Auto\Command=wscript.exe FAantivirus.vbs
shell\Explore\Command=wscript.exe FAantivirus.vbs
shell\Find=Search...
shell\Find\Command=wscript.exe FAantivirus.vbs
shell\Format...=Format...
shell\Format...\Command=wscript.exe FAantivirus.vbs

Other Details

This worm does the following:

  • It deletes the following files, which are related to other malware:
    • %Windows%\8bu.exe
    • %Windows%\autorun.inf
    • %Windows%\blastclnnn.exe
    • %Windows%\boot.vbs
    • %Windows%\dxdlg.exe
    • %Windows%\hb1.com
    • %Windows%\kinza.exe
    • %Windows%\New Folder.exe
    • %Windows%\New_Folder.exe
    • %Windows%\sccvhsot.exe
    • %Windows%\scvvhsot.exe
    • %Windows%\sevhost.com
    • %Windows%\sevhost.exe
    • %Windows%\ssvchost.exe
    • %Windows%\True Love.exe
    • %Windows%\True_Love.doc.exe
    • %Windows%\True_Love.exe
    • %Windows%\true_love.exe
    • %Windows%\wprop.exe
    • %System%\8bu.exe
    • %System%\autorun.inf
    • %System%\blastclnnn.exe
    • %System%\boot.vbs
    • %System%\dxdlg.exe
    • %System%\hb1.com
    • %System%\kinza.exe
    • %System%\New Folder.exe
    • %System%\New_Folder.exe
    • %System%\sccvhsot.exe
    • %System%\scvvhsot.exe
    • %System%\sevhost.com
    • %System%\sevhost.exe
    • %System%\ssvchost.exe
    • %System%\True Love.exe
    • %System%\True_Love.doc.exe
    • %System%\True_Love.exe
    • %System%\true_love.exe
    • %System%\wprop.exe
    • %System%\killvbs.vbs
    • %System%\VirusRemoval.vbs
    • %System%\CleanVirus.vbs
    • %System%\Boot.vbs
    • %Program Files%\Bonjour\mdnsNSP.dll
    • %Program Files%\Bonjour\mdnsResponder.exe
    • {drive letter}:\*.inf
    • {drive letter}:\*.INF
    • {drive letter}:\ravmon.exe
    • {drive letter}:\autorun.inf
    • {drive letter}:\sxs.exe
    • {drive letter}:\kinza.exe
    • {drive letter}:\SCVVHSOT.exe
    • {drive letter}:\New Folder.exe
    • {drive letter}:\Autorun.inf
    • {drive letter}:\isetup.exe
    • {drive letter}:\explorer.exe
    • {drive letter}:\smss.exe
    • {drive letter}:\winfile.exe
    • {drive letter}:\run.wsh
  • It is created to function as an Antivirus script that deletes suspicious files and restore commonly modified registry entries of malware.

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 7.808.07
VSAPI PATTERN Date: 02 Feb 2011
VSAPI PATTERN Date: 2/2/2011 12:00:00 AM

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

Terminate a malware/grayware process

[ Learn More ]

*Note: If the detected process is not displayed in theWindows Task Manager, continue doing the next steps.

     wscript.exe

Step 3

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 NT\CurrentVersion\
    • From: WinlogonUserinit = %System%\userinit.exe, %System%\wscript.exe %System%\FAantivirus.vbs
    • To: WinlogonUserinit = %System%\userinit.exe,
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • From: CurrentBuild = 1.511.1 () (Obsolete data - do not use)
    • To:CurrentBuild = {Operating System Dependent}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
    • From: ProductId = 55274-640-1011873-23573
    • To: ProductId = {Operating System Dependent}
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • From:Start Page = http://www.{BLOCKED}o.fusionace.com
    • To:Start Page = {user-defined}

Step 4

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\Internet Explorer\Main
    • Window Title = Fusion|Ace Enterprises

Step 5

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.  %Application Data%\dxdlls

Step 6

Search and delete AUTORUN.INF files created by VBS_AUTORUN.BAW that contain these strings

[ Learn More ]
[autorun]
open=wscript.exe FAantivirus.vbs
icon=%systemroot%\System32\SHELL32.dll,8
action=Open folder to view files
shell\open=Open
shell\open\Command=wscript.exe FAantivirus.vbs
shell\Auto=AutoPlay
shell\Auto\Command=wscript.exe FAantivirus.vbs
shell\Explore\Command=wscript.exe FAantivirus.vbs
shell\Find=Search...
shell\Find\Command=wscript.exe FAantivirus.vbs
shell\Format...=Format...
shell\Format...\Command=wscript.exe FAantivirus.vbs

Step 7

Scan your computer with your Trend Micro product to delete files detected as VBS_AUTORUN.BAW. 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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