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TROJ_FAKEAV.KAX
Malware type: Trojan
Destructive: No
Platform: Windows 2000, XP, Server 2003
Encrypted: Yes
In the wild: Yes

Overview


These malware use social engineering methods to lure users into performing certain actions that may, directly or indirectly, cause malicious routines to be performed. Specifically, it hijacks users’ known Internet browser so that infected users will be able install the rogue application.

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

It poses as an antispyware application that displays deceptive warnings and misleading scan results. It may also add other applications which it detects upon its installation. It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to a certain website asking for sensitive information, such as credit card numbers.

Technical Details


File size: 113,486 bytes
File type: EXE
Memory resident: Yes
Initial samples received date: 06 Sep 2010

Arrival Details

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

Installation

This Trojan creates the following folders:

  • %Program Files%\Win7 AV

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

It injects codes into the following process(es):

  • Chrome.exe
  • firefox.exe
  • IExplore.exe

Autostart Technique

This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\windiskdefend
Type = 10

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\windiskdefend
Start = 2

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\windiskdefend
ErrorControl = 1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\windiskdefend
ImagePath = %System%\windiskdefend.exe

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\windiskdefend
DisplayName = Windows Disk Defender

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\windiskdefend
ObjectName = LocalSystem

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\windiskdefend
Description = Provides hard disk defend and error check.

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Win7 AV = %Program Files%\Win7 AV\Win7 AV.exe

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Win7 AV

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_CLASSES_ROOT\CLSID\{C9C42510-9B41-42c1-9DCD-7282A2D07C61}
(Default) = Windows Defendor Web-module

HKEY_CLASSES_ROOT\CLSID\{C9C42510-9B41-42c1-9DCD-7282A2D07C61}\
InProcServer32
(Default) = %System%\windefWebModule.dll

HKEY_CLASSES_ROOT\CLSID\{C9C42510-9B41-42c1-9DCD-7282A2D07C61}\
InProcServer32
ThreadingModel = Apartment

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://initrd.{BLOCKED}v.com/ins/w7avf/0.000/35073951E80010002B1C20V30I7NA/NI/0000/1daf86729ab7e428aed65d56ae6b33d8d0377fb0
  • http://initrd.{BLOCKED}v.com/ins/w7avf/0.000/35073951E80010002B1C20V30I7NA/FL/0000/33ca75c798ceffa5693c41287e19cb6f364a9bc1

Other Details

Based on analysis of the codes, it has the following capabilities:

  • It injects codes to web browsers to display fake infection warnings.

It drops the following file(s)/component(s):

  • %Program Files%\\\\Win7 AV\\\\AxInterop.SHDocVw.dll
  • %Program Files%\\\\Win7 AV\\\\base001.dat
  • %Program Files%\\\\Win7 AV\\\\base002.dat
  • %Program Files%\\\\Win7 AV\\\\base003.dat
  • %Program Files%\\\\Win7 AV\\\\Interop.SHDocVw.dll
  • %Program Files%\\\\Win7 AV\\\\Win7 AV.exe
  • %Program Files%\\\\Win7 AV\\\\Win7Browser.exe
  • %Program Files%\\\\Win7 AV\\\\svhostqt.dll
  • %Program Files%\\\\Win7 AV\\\\svhostesl.dll
  • %Program Files%\\\\Win7 AV\\\\sbhostcl.dll
  • %System%\\\\msxml.dll
  • %System%\\\\windefWebModule.dll
  • %System%\\\\windiskdefend.exe
  • %System%\\\\windiskdefend.InstallState
  • %User Profile%\\Desktop\\Win7 AV.lnk

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.. %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.. %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.)

Rogue Antivirus Routine

This Trojan poses as an antispyware application that displays deceptive warnings and misleading scan results. It may also add other applications which it detects upon its installation.

It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to a certain website asking for sensitive information, such as credit card numbers.

Solution


Minimum scan engine: 8.900
VSAPI Pattern File: 7.440.07
VSAPI Pattern Release Date: 06 Sep 2010

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

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Win7 AV = %Program Files%\Win7 AV\Win7 AV.exe

Step 3

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.


  • In HKEY_CLASSES_ROOT\CLSID
    • {C9C42510-9B41-42c1-9DCD-7282A2D07C61}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects
    • {C9C42510-9B41-42c1-9DCD-7282A2D07C61}
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • Win7 AV

Step 4

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.
%Program Files%\Win7 AV

Step 5

Search and delete this file

[ 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.
%System%\msxml.dll
%System%\windefWebModule.dll
%System%\windiskdefend.exe
%System%\windiskdefend.InstallState
%User Profile%\Desktop\Win7 AV.lnk

Step 6

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

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.KAX. 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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Analysis By: Karl Dominguez

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