ALIASES:

Trojan:Win32/Neurevt.C (Microsoft); RDN/Generic.hra!cd (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Neurevt.bqt (Kaspersky); Mal/Wonton-J (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Downloader.Small.MTH (AVG)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This backdoor 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: 375,808 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 25 Feb 2015

Arrival Details

This backdoor 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 backdoor creates the following folders:

  • %Program Files%\Common Files\bett2f00

(Note: %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.)

Other System Modifications

This backdoor deletes the following files:

  • %Program Files%\Common Files\bett2f00\bfvjkphyr.exe:Zone.Identifier

(Note: %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 adds the following registry keys:

HKEY_CURRENT_USER\Software\Win7zip

HKEY_CURRENT_USER\Software\Classes\
CLSID\{20679BE5-A98A-284F-90C6-B152B9CEA1E9}\04200134\
CG1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
bfvjkphyr.exe

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Win7zip
Uuid = "{random values}"

Dropping Routine

This backdoor drops the following files:

  • %Program Files%\Common Files\bett2f00\desktop.ini

(Note: %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.)

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

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
    • Win7zip
  • In HKEY_CURRENT_USER\Software\Classes\CLSID\{20679BE5-A98A-284F-90C6-B152B9CEA1E9}\04200134
    • CG1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • bfvjkphyr.exe

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\Win7zip
    • Uuid = "{random values}"

Step 4

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.
  • %Program Files%\Common Files\bett2f00\desktop.ini

Step 5

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.
  • %Program Files%\Common Files\bett2f00

Step 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_NEUREVT.YYXX. 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 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Program Files%\Common Files\bett2f00\bfvjkphyr.exe:Zone.Identifier


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