TROJ_NEUREVT.X

 Analysis by: David John Agni

 ALIASES:

Trojan:Win32/Skeeyah.A!rfn (Microsoft)

 PLATFORM:

Windows

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

  • 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:

275,448 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Jun 2015

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 copies of itself into the affected system and executes them:

  • %ProgramData%\Windows Search 5.3.10\{random filename}.exe (for Windows Vista and above)
  • %Program Files%\Common Files\Windows Search 5.3.10\{random filename}.exe (for Windows XP and below)

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It drops the following files:

  • %User Temp%\{random filename}.js
  • %User Temp%\{random filename 1}
  • %User Temp%\{random filename 2}
  • %User Temp%\br.gif
  • %User Temp%\css_injector_13.css

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It creates the following folders:

  • %ProgramData%\Windows Search 5.3.10 (for Windows Vista and above)
  • %Program Files%\Common Files\Windows Search 5.3.10 (for Windows XP and below)

(Note: %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

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
Windows Search 5.3.10 = "%Program Files%\Common Files\Windows Search 5.3.10\{random filename}.exe" (for Windows XP and below)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Search 5.3.10 = "%Program Files%\Common Files\Windows Search 5.3.10\{random filename}.exe" (for Windows XP and below)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
Windows Search 5.3.10 = "%ProgramData%\Windows Search 5.3.10\{random filename}.exe" (for Windows Vista and above)

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Search 5.3.10 = "%ProgramData%\Windows Search 5.3.10\{random filename}.exe" (for Windows Vista and above)

It adds the following Image File Execution Options registry entries to automatically execute itself whenever certain applications are run:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{filename}.exe
Debugger = ""%ProgramData%\Windows Search 5.3.10\{random filename}.exe" /uac /ifeo" (for Windows Vista and above)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{filename}.exe
Debugger = ""%Program Files%\Common Files\Windows Search 5.3.10" /uac /ifeo" (for Windows XP and below)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\AppDataLow\
Software\{UID}

HKEY_CURRENT_USER\Software\AppDataLow\
Software\MyMailClient

HKEY_CURRENT_USER\Software\AppDataLow\
Google Updater (for Windows Vista and above)

HKEY_CURRENT_USER\Software\Logitech, Inc. (for Windows XP and below)

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\1
2500 = "3"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\2
2500 = "3"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2500 = "3"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\4
2500 = "3"

HKEY_CURRENT_USER\Software\AppDataLow\
Google Updater
LastUpdate = "{hex values}" (for Windows Vista and above)

HKEY_CURRENT_USER\Software\Logitech, Inc.
WindowLayout = "{hex values}" (for Windows XP and below)

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
NoProtectedModeBanner = "1"

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}ylaws402.ws
  • http://{BLOCKED}werss.com/power/logout.php

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.750

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete these 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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Windows Search 5.3.10 = "%Program Files%\Common Files\Windows Search 5.3.10\{random filename}.exe" (for Windows XP and below)
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Windows Search 5.3.10 = "%Program Files%\Common Files\Windows Search 5.3.10\{random filename}.exe" (for Windows XP and below)
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • Windows Search 5.3.10 = "%ProgramData%\Windows Search 5.3.10\{random filename}.exe" (for Windows Vista and above)
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Windows Search 5.3.10 = "%ProgramData%\Windows Search 5.3.10\{random filename}.exe" (for Windows Vista and above)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\{filename}.exe
    • Debugger = ""%ProgramData%\Windows Search 5.3.10\{random filename}.exe" /uac /ifeo" (for Windows Vista and above)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\{filename}.exe
    • Debugger = ""%Program Files%\Common Files\Windows Search 5.3.10" /uac /ifeo" (for Windows XP and below)

Step 5

Delete this registry key

[ 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_CURRENT_USER\Software\AppDataLow
    • Google Updater (for Windows Vista and above)
  • In HKEY_CURRENT_USER\Software
    • Logitech, Inc. (for Windows XP and below)

Step 6

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.
  • %ProgramData%\Windows Search 5.3.10 (for Windows Vista and above)
  • %Program Files%\Common Files\Windows Search 5.3.10 (for Windows XP and below)

Step 7

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.
  • %User Temp%\{random filename}.js
  • %User Temp%\{random filename 1}
  • %User Temp%\{random filename 2}
  • %User Temp%\br.gif
  • %User Temp%\css_injector_13.css

Step 8

Reset Internet security settings

[ Learn More ]

Step 9

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