Analysis by: Cris Nowell Pantanilla

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Potenitally Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Potenitally Unwanted Application may be manually installed by a user.

  TECHNICAL DETAILS

File Size: 712,824 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 25 Apr 2017

Arrival Details

This Potenitally Unwanted Application may be manually installed by a user.

Installation

This Potenitally Unwanted Application drops the following component file(s):

  • %User Temp%\{random 1}.log
  • %User Temp%\{random 2}.log
  • %User Temp%\ish{random numbers 1}\css\ie6_main.css
  • %User Temp%\ish{random numbers 1}\css\main.css
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\browse.css
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\button.css
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\checkbox.css
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random numbers 1}\css\sdk-ui
  • %User Temp%\ish{random numbers 1}\csshover3.htc
  • %User Temp%\ish{random numbers 1}\dat\upd.DAT
  • %User Temp%\ish{random numbers 1}\form.bmp.Mask
  • %User Temp%\ish{random numbers 1}\images\Close.png
  • %User Temp%\ish{random numbers 1}\images\Close_Hover.png
  • %User Temp%\ish{random numbers 1}\images\Color_Button.png
  • %User Temp%\ish{random numbers 1}\images\Color_Button_Hover.png
  • %User Temp%\ish{random numbers 1}\images\Grey_Button.png
  • %User Temp%\ish{random numbers 1}\images\Grey_Button_Hover.png
  • %User Temp%\ish{random numbers 1}\images\Loader.gif
  • %User Temp%\ish{random numbers 1}\images\Logo.png
  • %User Temp%\ish{random numbers 1}\images\Progress.png
  • %User Temp%\ish{random numbers 1}\images\ProgressBar.png
  • %User Temp%\ish{random numbers 1}\images\text-bg.png
  • %User Temp%\ish{random numbers 1}\locale\DE.locale
  • %User Temp%\ish{random numbers 1}\locale\EN.locale
  • %User Temp%\ish{random numbers 1}\locale\ES.locale
  • %User Temp%\ish{random numbers 1}\locale\FR.locale
  • %User Temp%\ish{random numbers 1}\locale\IT.locale
  • %User Temp%\ish{random numbers 1}\locale\PL.locale
  • %User Temp%\ish{random numbers 1}\locale\PT.locale
  • %User Temp%\ish{random numbers 1}\locale\RU.locale
  • %User Temp%\ish{random numbers 1}\locale\UA.locale
  • %User Temp%\is{random numbers 2)\{random numbers 3}_stp.EXE
  • %User Temp%\is{random numbers 2)\{random numbers 3}_stp.EXE.part
  • %Program Files%\Tweaks\File Extractor\fileextractor.exe
  • %Program Files%\Tweaks\File Extractor\7z.dll
  • %Program Files%\Tweaks\File Extractor\uninstall.exe
  • %Desktop%\File Extractor.lnk
  • %ProgramData%\Microsoft\Windows\Start Menu\Programs\Tweaks\File Extractor\File Extractor.lnk
  • %ProgramData%\Microsoft\Windows\Start Menu\Programs\Tweaks\File Extractor\uninstall.lnk

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.. %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.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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 creates the following folders:

  • %User Temp%\ish{random numbers 1}
  • %User Temp%\ish{random numbers 1}\css
  • %User Temp%\ish{random numbers 1}\css\sdk-ui
  • %User Temp%\ish{random numbers 1}\css\sdk-ui\images
  • %User Temp%\ish{random numbers 1}\dat
  • %User Temp%\ish{random numbers 1}\images
  • %User Temp%\ish{random numbers 1}\locale
  • %User Temp%\is{random numbers 2)
  • %Program Files%\Tweaks
  • %Program Files%\Tweaks\File Extractor
  • %ProgramData%\Microsoft\Windows\Start Menu\Programs\File Extractor

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.. %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.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in 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 Potenitally Unwanted Application adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
Tweaks File Extractor

Other Details

This Potenitally Unwanted Application connects to the following possibly malicious URL:

  • http://os.{BLOCKED}leextractorapp.com/CM_DS/?v=3.0&c=588699595
  • http://os2.{BLOCKED}leextractorapp.com/CM_DS/?v=3.0&c=588699595
  • http://rp.{BLOCKED}leextractorapp.com/?pcrc=1321774837
  • http://rp.{BLOCKED}leextractorapp.com/?pcrc=478362507
  • http://s3.{BLOCKED}onaws.com/Tweaks/distros/FileExtractorSetupG.exe

  SOLUTION

Minimum Scan Engine: 9.850

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
    • Tweaks File Extractor

Step 3

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.
%User Temp%\ish{random numbers 1}
%User Temp%\ish{random numbers 1}\css
%User Temp%\ish{random numbers 1}\css\sdk-ui
%User Temp%\ish{random numbers 1}\css\sdk-ui\images
%User Temp%\ish{random numbers 1}\dat
%User Temp%\ish{random numbers 1}\images
%User Temp%\ish{random numbers 1}\locale
%User Temp%\is{random numbers 2)
%Program Files%\Tweaks
%Program Files%\Tweaks\File Extractor
%ProgramData%\Microsoft\Windows\Start Menu\Programs\File Extractor

Step 4

Scan your computer with your Trend Micro product to delete files detected as PUA_INSTALLCORE.GW. 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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