Analysis by: Clive Fuentebella
ALIASES:

a variant of Win32/Packed.NSISmod.AM suspicious application (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This Potentially Unwanted Application arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 947,784 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 02 Aug 2019
Payload: Connects to URLs/IPs, Displays windows

Arrival Details

This Potentially Unwanted Application 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 Potentially Unwanted Application drops the following files:

  • {Malware file path}\install.log
  • %User Temp%\ns{Random characters}.tmp
  • %User Temp%\~ns{Random characters}.tmp\Un_A.exe
  • %User Temp%\~ns{Random characters}.tmp\Un_A.exe.p
  • %User Temp%\ns{Random characters}.tmp\System.dll
  • %User Temp%\ns{Random characters}.tmp\un.FileInfo.dll
  • %User Temp%\ns{Random characters}.tmp\RCWidgetPlugin.dll

(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 adds the following processes:

  • "%User Temp%\~ns{Random characters}.tmp\Un_A.exe" _?={Malware file path}\

(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).)

Other System Modifications

This Potentially Unwanted Application adds the following registry entries:

HKEY_CURRENT_USER\Software\{BLOCKED}5.com
UUID = {UUID} {Random number}

HKEY_CURRENT_USER\Software\{BLOCKED}5.com\
2345Explorer
ADValue = 1 {Random number}

HKEY_CURRENT_USER\Software\{BLOCKED}5.com\
2345Explorer
LADValue = {Random number} {Random number}

HKEY_CURRENT_USER\Software\{BLOCKED}5.com\
2345Explorer
UninstallBy = {Process used to uninstall 2345Explorer}

Information Theft

Upon execution of the affected application, it gathers the following information:

  • Product information (2345Explorer)
  • Product version

Other Details

This Potentially Unwanted Application connects to the following website to send and receive information:

  • http://t.{BLOCKED}an.{BLOCKED}5.com/stat/ie/index.php

It displays the following images:

It does the following:

  • User may opt to delete their personal configuration before uninstalling.

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 2.336.00
SSAPI PATTERN Date: 17 Sep 2020

Step 1

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 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

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\{BLOCKED}5.com
    • UUID={UUID} {Random number}
  • In HKEY_CURRENT_USER\Software\{BLOCKED}5.com\2345Explorer
    • ADValue=1 {Random number}
  • In HKEY_CURRENT_USER\Software\{BLOCKED}5.com\2345Explorer
    • LADValue={Random number} {Random number}
  • In HKEY_CURRENT_USER\Software\{BLOCKED}5.com\2345Explorer
    • UninstallBy={Process used to uninstall 2345Explorer}

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.
  • {Malware file path}\install.log
  • %User Temp%\ns{Random characters}.tmp
  • %User Temp%\~ns{Random characters}.tmp\Un_A.exe
  • %User Temp%\~ns{Random characters}.tmp\Un_A.exe.p
  • %User Temp%\ns{Random characters}.tmp\System.dll
  • %User Temp%\ns{Random characters}.tmp\un.FileInfo.dll
  • %User Temp%\ns{Random characters}.tmp\RCWidgetPlugin.dll

Step 5

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.2345Soft.JCI. 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 the following Trend Micro Support pages for more information:


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