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TROJ_NEUREVT.USPL

October 04, 2016
 Analysis by: Byron Jon Gelera
 ALIASES:

Win32/Neurevt.I (ESET-NOD32); Trojan:Win32/Neurevt!rfn (Microsoft); Trojan.Win32.Kovter.ipe (Kaspersky)

 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:

465,920 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

23 Sep 2016

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:

  • %All Users Profile%\Windows Update Engine\{random filename}.txt

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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 drops the following copies of itself into the affected system:

  • %All Users Profile%\Windows Update Engine\{random filename}.exe

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)

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)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{random filename}.exe

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}t.ru
  • {BLOCKED}ons.ru
  • {BLOCKED}sin.ru
  • {BLOCKED}eck.ru
  • {BLOCKED}i.ru
  • {BLOCKED}me.ru

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

12.794.06

FIRST VSAPI PATTERN DATE:

23 Sep 2016

VSAPI OPR PATTERN File:

12.795.00

VSAPI OPR PATTERN Date:

24 Sep 2016

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 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\Internet Settings\Zones\1
    • 2500 = "3"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\2
    • 2500 = "3"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
    • 2500 = "3"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\4
    • 2500 = "3"
  • In HKEY_CURRENT_USER\Software\AppDataLow\Google Updater
    • LastUpdate = "{hex values}" (for Windows Vista and above)
  • In HKEY_CURRENT_USER\Software\Logitech, Inc.
    • WindowLayout = "{hex values}" (for Windows XP and below)
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • NoProtectedModeBanner = "1"

Step 5

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\AppDataLow\Software
    • MyMailClient
  • 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)
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • {random filename}.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.  
  • %All Users Profile%\Windows Update Engine\{random filename}.txt

Step 7

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

Step 8

The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.

  • In HKEY_CURRENT_USER\Software\AppDataLow\Software
    • {UID}


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