Analysis by: Mc Justine De Guzman

ALIASES:

Win32/InstallCore.Gen.A potentially unwanted application (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

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: 799,876 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 18 Apr 2022
Payload: Connects to URLs/IPs, Drops files

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 adds the following folders:

  • %User Temp%\ish{random}

(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 files:

  • %Program Files%\is{random}.log
  • %User Temp%\{random}.log
  • %User Temp%\{random}_Update.exe
  • %User Temp%\ICReinstall_{Malware filename}.exe
  • %User Temp%\is{random}\{random}_stp.EXE
  • %User Temp%\is{random}\{random}_stp.EXE.part
  • %User Temp%\ish{random}\bootstrap_{random}.html
  • %User Temp%\ish{random}\css\ie6_main.css
  • %User Temp%\ish{random}\css\main.css
  • %User Temp%\ish{random}\css\sdk-ui\browse.css
  • %User Temp%\ish{random}\css\sdk-ui\button.css
  • %User Temp%\ish{random}\css\sdk-ui\checkbox.css
  • %User Temp%\ish{random}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\ish{random}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random}\csshover3.htc
  • %User Temp%\ish{random}\dat\upd.DAT
  • %User Temp%\ish{random}\form.bmp.Mask
  • %User Temp%\ish{random}\images\Close_Hover.png
  • %User Temp%\ish{random}\images\Close.png
  • %User Temp%\ish{random}\images\Color_Button_Hover.png
  • %User Temp%\ish{random}\images\Color_Button.png
  • %User Temp%\ish{random}\images\Grey_Button_Hover.png
  • %User Temp%\ish{random}\images\Grey_Button.png
  • %User Temp%\ish{random}\images\Loader.gif
  • %User Temp%\ish{random}\images\Logo.png
  • %User Temp%\ish{random}\images\Progress.png
  • %User Temp%\ish{random}\images\ProgressBar.png
  • %User Temp%\ish{random}\images\text-bg.png
  • %User Temp%\ish{random}\locale\DE.locale
  • %User Temp%\ish{random}\locale\EN.locale
  • %User Temp%\ish{random}\locale\ES.locale
  • %User Temp%\ish{random}\locale\FR.locale
  • %User Temp%\ish{random}\locale\IT.locale
  • %User Temp%\ish{random}\locale\PL.locale
  • %User Temp%\ish{random}\locale\PT.locale
  • %User Temp%\ish{random}\locale\RU.locale
  • %User Temp%\ish{random}\locale\UA.locale
  • %Desktop%\Continue File Opener Installation.lnk

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %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).. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Download Routine

This Potentially Unwanted Application connects to the following URL(s) to download its component file(s):

  • http://s3.a{BLOCKED}ws.com/Tweaks/distros/FileOpenerSetupG.exe

Other Details

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

  • http://ww25.os2.th{BLOCKED}app.com/CM_DS/?v=3.0&c=595283091&subid1=20220503-1734-39bb-9089-9d45d9de8e41
  • http://os2.th{BLOCKED}pp.com/CM_DS/?v=3.0&c=595283091

It does the following:

  • It opens the following website through browser:
    • http://th{BLOCKED}app.com/file-opener/welcome/oc/?iv=0

  SOLUTION

Minimum Scan Engine: 9.800
SSAPI PATTERN File: 2.507.00
SSAPI PATTERN Date: 18 Apr 2022

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:

    • Ransom.Win32.TRX.XXPE50FSX021

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

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.
  • %Program Files%\is{random}.log
  • %User Temp%\{random}.log
  • %User Temp%\{random}_Update.exe
  • %User Temp%\ICReinstall_{Malware filename}.exe
  • %User Temp%\is{random}\{random}_stp.EXE
  • %User Temp%\is{random}\{random}_stp.EXE.part
  • %User Temp%\ish{random}\bootstrap_{random}.html
  • %User Temp%\ish{random}\css\ie6_main.css
  • %User Temp%\ish{random}\css\main.css
  • %User Temp%\ish{random}\css\sdk-ui\browse.css
  • %User Temp%\ish{random}\css\sdk-ui\button.css
  • %User Temp%\ish{random}\css\sdk-ui\checkbox.css
  • %User Temp%\ish{random}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\ish{random}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random}\csshover3.htc
  • %User Temp%\ish{random}\dat\upd.DAT
  • %User Temp%\ish{random}\form.bmp.Mask
  • %User Temp%\ish{random}\images\Close_Hover.png
  • %User Temp%\ish{random}\images\Close.png
  • %User Temp%\ish{random}\images\Color_Button_Hover.png
  • %User Temp%\ish{random}\images\Color_Button.png
  • %User Temp%\ish{random}\images\Grey_Button_Hover.png
  • %User Temp%\ish{random}\images\Grey_Button.png
  • %User Temp%\ish{random}\images\Loader.gif
  • %User Temp%\ish{random}\images\Logo.png
  • %User Temp%\ish{random}\images\Progress.png
  • %User Temp%\ish{random}\images\ProgressBar.png
  • %User Temp%\ish{random}\images\text-bg.png
  • %User Temp%\ish{random}\locale\DE.locale
  • %User Temp%\ish{random}\locale\EN.locale
  • %User Temp%\ish{random}\locale\ES.locale
  • %User Temp%\ish{random}\locale\FR.locale
  • %User Temp%\ish{random}\locale\IT.locale
  • %User Temp%\ish{random}\locale\PL.locale
  • %User Temp%\ish{random}\locale\PT.locale
  • %User Temp%\ish{random}\locale\RU.locale
  • %User Temp%\ish{random}\locale\UA.locale
  • %Desktop%\Continue File Opener Installation.lnk

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.
  • %User Temp%\ish{random}

Step 6

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.InstallCore.MANHOCBM. 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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