Backdoor.Win32.NETWIRED.FCD

June 26, 2020
 Analysis by: Bren Matthew Ebriega
 ALIASES:

a variant of Win32/Injector.EJCP trojan (NOD32); Trojan.Win32.Krypt (IKARUS)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

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.

It executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.

It steals certain information from the system and/or the user.

  TECHNICAL DETAILS

File Size:

348,160 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

22 Jun 2020

Payload:

Connects to URLs/IPs, Steals information

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 adds the following processes:

  • {Malware Path}\{Malware Filename}.exe

It creates the following folders:

  • %Application Data%\Logs

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • VVJTVMlV

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
- = {Malware Path}\{Malware Filename}.exe

Other System Modifications

This Backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\NetWire
HostId = NEW

HKEY_CURRENT_USER\Software\NetWire
Install Date = {Install Date and Time}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\-
StubPath = {Malware Path}\{Malware Filename}.exe

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • List Running Processes
  • List Drive Information
  • Perform Keylogging Routine
  • Get Logon Sessions
  • List TCP and UDP Listening Ports
  • Download & execute files on the affected system
  • Execute Command Shell
  • List files in a directory
  • Terminate Processes
  • Get File or Process Information

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}.{BLOCKED}.131.184:4095

However, as of this writing, the said sites are inaccessible.

Dropping Routine

This Backdoor drops the following files:

  • %User Temp%\{Random Characters}.bat → For Self Deletion

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It drops the following file(s), which it uses for its keylogging routine:

  • %Application Data%\Logs\{DD-MM-YYYY}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Information Theft

This Backdoor steals the following information:

  • Credentials in the following protocol:
    • POP3
    • IMAP
    • HTTP
    • SMTP
    • EAS
  • System Information:
    • Computer Name
    • Current User Name
    • OS Version
    • Product Version
    • Processor Information

It attempts to get stored information such as user names, passwords, and hostnames from the following browsers:

  • Opera
  • Yandex Browser
  • Purple
  • Comodo Dragon
  • Chromium
  • Internet Explorer
  • Google Chrome
  • Brave
  • Mozilla Seamonkey
  • Mozilla Firefox

It attempts to steal stored email credentials from the following:

  • Mozilla Thunderbird
  • Microsoft Outlook

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.948.03

FIRST VSAPI PATTERN DATE:

23 Jun 2020

VSAPI OPR PATTERN File:

15.949.00

VSAPI OPR PATTERN Date:

24 Jun 2020

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • Troj.Win32.TRX.XXPE50FFF036

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

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\Run
    • - = {Malware Path}\{Malware Filename}.exe
  • In HKEY_CURRENT_USER\Software\NetWire
    • HostId = NEW
  • In HKEY_CURRENT_USER\Software\NetWire
    • Install Date = {Install Date and Time}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\-
    • StubPath = {Malware Path}\{Malware Filename}.exe

Step 6

Search and delete these folders

[ 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.
  • %Application Data%\Logs

Step 7

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.
  • %Application Data%\Logs\{DD-MM-YYYY}
  • %User Temp%\{Random Characters}.bat
DATA_GENERIC
  • Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7 and Windows Server 2008 (R2).

    • Step 8

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.NETWIRED.FCD. 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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