Analysis by: Rhena Inocencio

ALIASES:

Trojan-FakeAV.Win32.CProtection.qrf (Kaspersky)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size: 236,544 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 Apr 2013

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 file(s)/component(s):

  • %All Users Profile%\Application Data\{random file name}
  • %Application Data%\{random file name}
  • %User Temp%\{random file name}
  • %User Profile%\Templates\{random file name}
  • %Application Data%\Microsoft\Windows\Templates\{random file name} (for Windows Vista and 7)
  • %All Users Profile%\{random file name} (for Windows Vista and 7)
  • %AppDataLocal%\{random file name} (for Windows Vista and 7)

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
Default = ""{malware path and filename}" -a "%1" %*"

HKEY_CURRENT_USER\Software\Classes\
{random}\shell\open\
command
Default = ""{malware path and filename}" -a "%1" %*"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\FIREFOX.EXE\shell\
open\command
Default = ""{malware path and filename}" -a "%Program Files%\Mozilla Firefox\firefox.exe""

(Note: The default value data of the said registry entry is "%Program Files%\Mozilla Firefox\firefox.exe".)

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\FIREFOX.EXE\shell\
safemode\command
Default = ""{malware path and filename}" -a "%Program Files%\Mozilla Firefox\firefox.exe" -safe-mode""

(Note: The default value data of the said registry entry is "%Program Files%\Mozilla Firefox\firefox.exe" -safe-mode".)

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\IEXPLORE.EXE\shell\
open\command
Default = ""{malware path and filename}" -a "%Program Files%\Internet Explorer\iexplore.exe""

(Note: The default value data of the said registry entry is "%Program Files%\Internet Explorer\iexplore.exe".)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}0.com/{random number}
  • http://{BLOCKED}ayms.com/{random number}
  • http://{BLOCKED}ayms.com/?do=payment&ver={number}&sid={number}&sn={number}

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.886.06
FIRST VSAPI PATTERN DATE: 30 Apr 2013

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Identify and terminate files detected as TROJ_FAKEAV.LQN

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. 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.
  3. 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\Classes\.exe\shell\open\command
    • Default = ""{malware path and filename}" -a "%1" %*"
  • In HKEY_CURRENT_USER\Software\Classes\{random}\shell\open\command
    • Default = ""{malware path and filename}" -a "%1" %*"

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\Clients\StartMenuInternet\FIREFOX.EXE\shell\open\command
    • From: Default = ""{malware path and filename}" -a "%Program Files%\Mozilla Firefox\firefox.exe""
      To: Default = "%Program Files%\Mozilla Firefox\firefox.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\FIREFOX.EXE\shell\safemode\command
    • From: Default = ""{malware path and filename}" -a "%Program Files%\Mozilla Firefox\firefox.exe" -safe-mode""
      To: Default = "%Program Files%\Mozilla Firefox\firefox.exe" -safe-mode"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\IEXPLORE.EXE\shell\open\command
    • From: Default = ""{malware path and filename}" -a "%Program Files%\Internet Explorer\iexplore.exe""
      To: Default = "%Program Files%\Internet Explorer\iexplore.exe"

Step 5

Search and delete these files

[ Learn More ]
There may be some 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.
  • %All Users Profile%\Application Data\{random file name}
  • %Application Data%\{random file name}
  • %User Temp%\{random file name}
  • %User Profile%\Templates\{random file name}
  • %Application Data%\Microsoft\Windows\Templates\{random file name}
  • %All Users Profile%\{random file name}
  • %AppDataLocal%\{random file name}

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.LQN. 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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