TROJ_FAKEAV.TIN

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

Rogue:Win32/FakeRean (Microsoft), BackDoor-FJW!F41FF0C78F15 (McAfee), FraudTool.Win32.FakeRean (Sunbelt), W32/FakeAV.PXPL!tr (Fortinet), Trojan-PSW.Win32.Tepfer (Ikarus), Win32/Kryptik.ASKH trojan (ESET), Trj/Tepfer.A (Panda), Trojan.FakeAV.01657 (VBA32)

 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:

204,998 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Feb 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 files:

  • %User Temp%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • {All Users' Profile}\Application Data\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl - for Windows OS other than Vista and 7
  • %Application Data%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl - for Windows OS other than Vista and 7
  • %User Profile%\Templates\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl - for Windows OS other than Vista and 7
  • %ProgramData%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl - for Windows Vista and 7 only
  • {All Users' Profile}\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl - for Windows Vista and 7 only
  • %AppDataLocal%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl - for Windows Vista and 7 only
  • %Application Data%\Microsoft\Windows\Templates\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl - for Windows Vista and 7 only

(Note: %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.. %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 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.. %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This is usually C:\ProgramData in Windows Vista and 7, or C:\Program Files on Windows 2000, XP (32-bit), and Server 2003, or C:\Program Files (x86) on Windows XP (64-bit).. %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\Microsoft\
Windows - for Windows OS other than Vista and 7
Identity = "b570ddac"

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

It modifies the following registry entries:

HKEY_CLASSES_ROOT\exefile\shell\
open\command
(Default) = "{malware path and file name} -a "%1" %*"

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

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

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

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

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.104.243/{random characters}
  • http://{BLOCKED}sdlinksfill.com/data.exe

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.724.03

FIRST VSAPI PATTERN DATE:

13 Feb 2013

VSAPI OPR PATTERN File:

9.725.00

VSAPI OPR PATTERN Date:

13 Feb 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

Scan your computer with your Trend Micro product and note files detected as TROJ_FAKEAV.TIN

Step 3

Restart in Safe Mode

[ Learn More ]

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\Windows
    • Identity = "b570ddac"
  • In HKEY_CURRENT_USER\Software\Classes\.exe\shell\open\command
    • (Default) = "{malware path and file name}" -a "%1" %*"

Step 5

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_CLASSES_ROOT\exefile\shell\open\command
    • From: (Default) = "{malware path and file name} -a "%1" %*"
      To: (Default) = "%1" %*
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\IEXPLORE.EXE\shell\open\command
    • From: (Default) = ""{malware path and file name} -a "%Program Files%\Internet Explorer\iexplore.exe""
      To: (Default) = %Program Files%\Internet Explorer\iexplore.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\FIREFOX.EXE\shell\safemode\command
    • From: (Default) = ""{malware path and file name}" -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\FIREFOX.EXE\shell\open\command
    • From: (Default) = ""{malware path and file name}" -a "%Program Files%\Mozilla Firefox\firefox.exe""
      To: (Default) = %Program Files%\Mozilla Firefox\firefox.exe

Step 6

Search and delete this file

[ 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.
  • %User Temp%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • {All Users' Profile}\Application Data\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • %Application Data%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • %User Profile%\Templates\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • %ProgramData%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • {All Users' Profile}\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • %AppDataLocal%\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl
  • %Application Data%\Microsoft\Windows\Templates\1pb78m8n6he1l1565b3k36w7o7of8ksb88y53s63tpqg0vl

Step 7

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