TROJ_FAKEAV.KLE


 ALIASES:

TrojanDownloader:Win32/Zemot (Microsoft); RDN/Downloader.a!rp (McAfee); Trojan.FakeAV (Symantec); Trojan-Spy.Win32.Zbot.tjdl (Kaspersky); Troj/Agent-AHQI (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Downloader.Generic13.CGUV (AVG)

 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

145,408 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

16 Jul 2014

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 creates the following folders:

  • %User Profile%\Application Data\Ofkyuwp

(Note: %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.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Tasekauqefi = "%User Profile%\Ofkyuwp\vazitau.exe "

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Tasekauqefi = "%User Profile%\Ofkyuwp\vazitau.exe "

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Chcvifhsno

HKEY_CURRENT_USER\SOFTWARE\Chcvifhsno

HKEY_LOCAL_MACHINE\Software\Classes\
CLSID\{84E66CF1-104E-85F7-2DBC-2968139AEFA6}

HKEY_CURRENT_USER\SOFTWARE\AVygrA

HKEY_LOCAL_MACHINE\SOFTWARE\AVygrA

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Chcvifhsno
License = "5c8"

HKEY_CURRENT_USER\Software\Chcvifhsno
License = "5c8"

HKEY_CURRENT_USER\Software\AVygrA
dynamicdata = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\AVygrA
dynamicdata = "{random values}"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Session Manager\SubSystems
Windows = "{random characters}"

(Note: The default value data of the said registry entry is {random values}.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\UpdateFlashPlayer_bed9a114.exe
  • %User Temp%\UpdateFlashPlayer_0cb4a8f3.exe
  • %User Temp%\UpdateFlashPlayer_bc1d2c2c.exe
  • %User Temp%\UpdateFlashPlayer_eae950f1.exe
  • %User Profile%\Ofkyuwp\vazitau.exe
  • %Windows%\Tasks\Security Center Update - 663904567.job
  • %System%\icseheis.exe

(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.. %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.. %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}inges.com/b/shoe/1480
  • http://{BLOCKED}inges.com/caguest-book/jquery
  • http://{BLOCKED}inges.com/caguest-book/ajax
  • http://{BLOCKED}inges.com/b/letr/05BFDE91ED67D3AD636A4148
  • http://{BLOCKED}inges.com/b/letr/40D273A1790250F3F70FC216
  • {BLOCKED}.116.41
  • {BLOCKED}.2.219
  • {BLOCKED}.62.190
  • {BLOCKED}.172.96

It deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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

Restart in Safe Mode

[ Learn More ]

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_LOCAL_MACHINE\SOFTWARE
    • Chcvifhsno
  • In HKEY_CURRENT_USER\SOFTWARE
    • Chcvifhsno
  • In HKEY_LOCAL_MACHINE\Software\Classes\CLSID
    • {84E66CF1-104E-85F7-2DBC-2968139AEFA6}
  • In HKEY_CURRENT_USER\SOFTWARE
    • AVygrA
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • AVygrA

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Tasekauqefi = "%User Profile%\Ofkyuwp\vazitau.exe "
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Tasekauqefi = "%User Profile%\Ofkyuwp\vazitau.exe "
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Chcvifhsno
    • License = "5c8"
  • In HKEY_CURRENT_USER\Software\Chcvifhsno
    • License = "5c8"
  • In HKEY_CURRENT_USER\Software\AVygrA
    • dynamicdata = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AVygrA
    • dynamicdata = "{random values}"

Step 5

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager\SubSystems
    • From: Windows = "{random characters}"
      To: Windows = ""{random values}""

Step 6

Search and delete these components

[ Learn More ]
There may be some components 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%\UpdateFlashPlayer_bed9a114.exe
  • %User Temp%\UpdateFlashPlayer_0cb4a8f3.exe
  • %User Temp%\UpdateFlashPlayer_bc1d2c2c.exe
  • %User Temp%\UpdateFlashPlayer_eae950f1.exe
  • %User Profile%\Ofkyuwp\vazitau.exe
  • %Windows%\Tasks\Security Center Update - 663904567.job
  • %System%\icseheis.exe

Step 7

Search and delete this folder

[ 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.
  • %User Profile%\Application Data\Ofkyuwp

Step 8

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