TROJ_FAKEXPA.DR

 Analysis by: Sabrina Lei Sioting

 ALIASES:

[Microsoft] Rogue:Win32/FakeXPA; [Kaspersky] Packed.Win32.Katusha.e;

 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

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.

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:

2,152,960 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

13 Apr 2011

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 files:

  • %system root%\Documents and Settings\All Users\Start Menu\E-Set 2011\E-Set Antivirus 2011.lnk
  • %system root%\Documents and Settings\All Users\Start Menu\E-Set 2011\Uninstall.lnk
  • %Desktop%\E-Set Antivirus 2011.lnk

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

It drops the following copies of itself into the affected system:

  • %Program Files%\E-Set 2011\e-set.exe
  • %System%\msiexecs.exe

(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.)

It creates the following folders:

  • %system root%\Documents and Settings\All Users\Start Menu\E-Set 2011
  • %Program Files%\E-Set 2011

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

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
E-Set 2011 = %Program Files%\E-Set 2011\e-set.exe

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
chrome.exe
Debugger = msiexecs.exe -sb

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
firefox.exe
Debugger = msiexecs.exe -sb

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
iexplore.exe
Debugger = msiexecs.exe -sb

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
opera.exe
Debugger = msiexecs.exe -sb

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
safari.exe
Debugger = msiexecs.exe -sb

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

HKEY_CURRENT_USER\Software\{random}

Rogue Antivirus Routine

This Trojan 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.

NOTES:
It displays the following graphical user interface (GUI):

If users decide to purchase the rogue product, they are then directed to the following site asking for sensitive information, such as credit card numbers:

    http://{BLOCKED}e.shopbestgoods.com

It may gather the following information if the user chooses to activate the product:

  • Credit card information (i.e. card type, card number, expiration date, security code)
  • Contact information (i.e. name, address, email, phone number)

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

7.968.12

FIRST VSAPI PATTERN DATE:

13 Apr 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

Identify and terminate files detected as TROJ_FAKEXPA.DR

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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
    • E-Set 2011 = %Program Files%\E-Set 2011\e-set.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\chrome.exe
    • Debugger = msiexecs.exe -sb
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\firefox.exe
    • Debugger = msiexecs.exe -sb
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\iexplore.exe
    • Debugger = msiexecs.exe -sb
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\opera.exe
    • Debugger = msiexecs.exe -sb
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\safari.exe
    • Debugger = msiexecs.exe -sb

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.

  • In HKEY_CURRENT_USER\Software\
    • {random}

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.
%system root%\Documents and Settings\All Users\Start Menu\E-Set 2011
%Program Files%\E-Set 2011

Step 6

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. %Desktop%\E-Set Antivirus 2011.lnk

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEXPA.DR. 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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