Analysis by: Arvin Roi Macaraeg
ALIASES:

Win32/InstallCore.BN 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

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.

  TECHNICAL DETAILS

File Size: 793,536 bytes
File Type: , EXE
Memory Resident: No
Initial Samples Received Date: 05 Jul 2013

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:

  • %User Temp%\is{random numbers}\{random numbers}.cfg;
  • %User Temp%\is{random numbers}\{random numbers}.cfg;
  • %User Temp%\is{random numbers}\{random numbers}_Setup.CIS;
  • %User Temp%\{random number}.log
  • %User Temp%\ish{random number}\blank.gif
  • %User Temp%\ish{random number}\css\buttons.css
  • %User Temp%\ish{random number}\css\ie6_main.css
  • %User Temp%\ish{random number}\css\main.css
  • %User Temp%\ish{random number}\css\browse.css
  • %User Temp%\ish{random number}\css\sdk-ui\button.css
  • %User Temp%\ish{random number}\css\sdk-ui\checkbox.css
  • %User Temp%\ish{random number}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random number}\DAT\DSiteU.dat
  • %User Temp%\ish{random number}\images\back-button.png
  • %User Temp%\ish{random number}\images\back-over.png
  • %User Temp%\ish{random number}\images\back.png
  • %User Temp%\ish{random number}\images\Bg.gif
  • %User Temp%\ish{random number}\images\close-button.png
  • %User Temp%\ish{random number}\images\close_button.png
  • %User Temp%\ish{random number}\images\finish-button.png
  • %User Temp%\ish{random number}\images\icon.png
  • %User Temp%\ish{random number}\images\loader.gif
  • %User Temp%\ish{random number}\images\next-button-disabled.png
  • %User Temp%\ish{random number}\images\next-button-es.png
  • %User Temp%\ish{random number}\images\next-button-over.png
  • %User Temp%\ish{random number}\images\next-button.png
  • %User Temp%\ish{random number}\images\progress-bg.png
  • %User Temp%\ish{random number}\images\Progress.png
  • %User Temp%\ish{random number}\images\ProgressBar.png
  • %User Temp%\ish{random number}\license\DE.license.txt
  • %User Temp%\ish{random number}\license\EN.license.txt
  • %User Temp%\ish{random number}\locale\EN.locale
  • %User Temp%\ish{random number}\sdk\exceptlist.txt
  • %User Temp%\{random number}_Update.exe
  • %User Temp%\{random number}.exe

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

It adds the following processes:

  • "%User Temp%\{random number}_Update.exe" /install /ProdName="Ultimate Codec" /unnm="Update for Ultimate Codec"
  • %System%\cmd.exe /d /c TIMEOUT 3 & cmd /d /c cmd /d /c cmd /d /c cmd /d /c cmd /d /c del "%User Temp%\{random number}.EXE"

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It creates the following folders:

  • %User Temp%\ish{random number}\css
  • %User Temp%\ish{random number}\css\sdk-ui
  • %User Temp%\ish{random number}\DAT
  • %User Temp%\ish{random number}\images
  • %User Temp%\ish{random number}\license
  • %User Temp%\ish{random number}\sdk

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

Other System Modifications

This Potentially Unwanted Application adds the following registry entries:

HKEY_CURRENT_USER\Software\InstallCore\
Uninstall\{Random}
uninstall = {Random}

HKEY_CURRENT_USER\Software\InstallCore\
Uninstall\{Random}
add_desc = {Random}

HKEY_CURRENT_USER\Software\InstallCore\
Uninstall\{Random}
add_link = {Random}

Other Details

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

  • http://{BLOCKED}s.{BLOCKED}tcodecpackapp.com/v1.0.1/?v=3.0&c=229987418
  • http://{BLOCKED}u.{BLOCKED}tcodecpackapp.com/app/Cmp/codecpack.cis
  • http://{BLOCKED}u.{BLOCKED}tcodecpackapp.com/ofr/DealPly/Dealply.cis

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 2.121.00
SSAPI PATTERN Date: 22 Nov 2018

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

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\InstallCore\Uninstall\{Random}
    • uninstall = "{Random}"
  • In HKEY_CURRENT_USER\Software\InstallCore\Uninstall\{Random}
    • add_desc = "{Random}"
  • In HKEY_CURRENT_USER\Software\InstallCore\Uninstall\{Random}
    • add_link = "{Random}"

Step 4

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 number}\css
  • %User Temp%\ish{random number}\css\sdk-ui
  • %User Temp%\ish{random number}\DAT
  • %User Temp%\ish{random number}\images
  • %User Temp%\ish{random number}\license
  • %User Temp%\ish{random number}\sdk

Step 5

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.
  • %User Temp%\is{random numbers}\{random numbers}.cfg;
  • %User Temp%\is{random numbers}\{random numbers}.cfg;
  • %User Temp%\is{random numbers}\{random numbers}_Setup.CIS;
  • %User Temp%\{random number}.log
  • %User Temp%\ish{random number}\blank.gif
  • %User Temp%\ish{random number}\css\buttons.css
  • %User Temp%\ish{random number}\css\ie6_main.css
  • %User Temp%\ish{random number}\css\main.css
  • %User Temp%\ish{random number}\css\\browse.css
  • %User Temp%\ish{random number}\css\sdk-ui\button.css
  • %User Temp%\ish{random number}\css\sdk-ui\checkbox.css
  • %User Temp%\ish{random number}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random number}\DAT\DSiteU.dat
  • %User Temp%\ish{random number}\images\back-button.png
  • %User Temp%\ish{random number}\images\back-over.png
  • %User Temp%\ish{random number}\images\back.png
  • %User Temp%\ish{random number}\images\Bg.gif
  • %User Temp%\ish{random number}\images\close-button.png
  • %User Temp%\ish{random number}\images\close_button.png
  • %User Temp%\ish{random number}\images\finish-button.png
  • %User Temp%\ish{random number}\images\icon.png
  • %User Temp%\ish{random number}\images\loader.gif
  • %User Temp%\ish{random number}\images\next-button-disabled.png
  • %User Temp%\ish{random number}\images\next-button-es.png
  • %User Temp%\ish{random number}\images\next-button-over.png
  • %User Temp%\ish{random number}\images\next-button.png
  • %User Temp%\ish{random number}\images\progress-bg.png
  • %User Temp%\ish{random number}\images\Progress.png
  • %User Temp%\ish{random number}\images\ProgressBar.png
  • %User Temp%\ish{random number}\license\DE.license.txt
  • %User Temp%\ish{random number}\license\EN.license.txt
  • %User Temp%\ish{random number}\locale\EN.locale
  • %User Temp%\ish{random number}\sdk\exceptlist.txt
  • %User Temp%\{random number}_Update.exe
  • %User Temp%\{random number}.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as PUA.WIN32.INSTALLCORE.GD. 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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