Analysis by: Pearl Charlaine Espejo
ALIASES:

PUP.Optional.InstallCore (Malwarebytes); InstallCore.MZ (AVG); Trojan.Skintrim.8847 (BitDefender); a variant of Win32/InstallCore.MB potentially unwanted (ESET-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: 686,048 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 03 Feb 2017

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%\{random filename}.log
  • %User Temp%\is{random}\css\ie6_main.css
  • %User Temp%\is{random}\css\main.css
  • %User Temp%\is{random}\css\sdk-ui\browse.css
  • %User Temp%\is{random}\css\sdk-ui\button.css
  • %User Temp%\is{random}\css\sdk-ui\checkbox.css
  • %User Temp%\is{random}\css\sdk-ui\images\button-bg.png
  • %User Temp%\is{random}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\is{random}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\is{random}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\is{random}\css\sdk-ui\progress-bar.css
  • %User Temp%\is{random}\csshover3.htc
  • %User Temp%\is{random}\DAT\upd.DAT
  • %User Temp%\is{random}\images\BG.gif
  • %User Temp%\is{random}\images\BG_gray.gif
  • %User Temp%\is{random}\images\Close.png
  • %User Temp%\is{random}\images\Close_gray.png
  • %User Temp%\is{random}\images\Close_Hover.png
  • %User Temp%\is{random}\images\Close_Hover_gray.png
  • %User Temp%\is{random}\images\Color_Button.png
  • %User Temp%\is{random}\images\Color_Button_gray.png
  • %User Temp%\is{random}\images\Color_Button_Hover.png
  • %User Temp%\is{random}\images\Color_Button_Hover_gray.png
  • %User Temp%\is{random}\images\Grey_Button.png
  • %User Temp%\is{random}\images\Grey_Button_Hover.png
  • %User Temp%\is{random}\images\icon.png
  • %User Temp%\is{random}\images\icon_gray.png
  • %User Temp%\is{random}\images\Loader.gif
  • %User Temp%\is{random}\images\Progress.png
  • %User Temp%\is{random}\images\ProgressBar.png
  • %User Temp%\is{random}\images\ssClose_Hover.png
  • %User Temp%\is{random}\images\xxClose.png
  • %User Temp%\is{random}\images\xxProgressBar.png
  • %User Temp%\is{random}\locale\EN.locale
  • %User Temp%\is{random}\bootstrap_28882.html
  • %User Temp%\is{random}\1091533_stp.CIS
  • %User Temp%\is{random}.flat
  • %User Temp%\is{random}\1091533_stp\OpenItSetup.exe
  • %User Temp%\ns{random}.tmp
  • %Program Files%\OpenIt\Open It!\openit.exe
  • %Program Files%\OpenIt\Open It!\7z.dll
  • %Program Files%\OpenIt\Open It!\QtCore4.dll
  • %Program Files%\OpenIt\Open It!\QtGui4.dll
  • %Program Files%\OpenIt\Open It!\libgcc_s_dw2-1.dll
  • %Program Files%\OpenIt\Open It!\libstdc++-6.dll
  • %Program Files%\OpenIt\Open It!\mingwm10.dll
  • %Program Files%\OpenIt\Open It!\uninstall.exe
  • %Desktop%\Open It!.lnk
  • %All Users Profile%\Start Menu\Programs\Open It!\Open It!.lnk
  • %All Users Profile%\Start Menu\Programs\Open It!\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.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)

It creates the following folders:

  • %User Temp%\is{random}
  • %All Users Profile%\Start Menu\Programs\Open It!
  • %Program Files%\OpenIt
  • %Program Files%\OpenIt\Open It!

(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.. %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)

Other System Modifications

This potentially unwanted application adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
DisplayName = "Open It!"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
UninstallString = ""%Program Files%\OpenIt\Open It!\uninstall.exe""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
QuietUninstallString = ""%Program Files%\OpenIt\Open It!\uninstall.exe" /S"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
InstallLocation = ""%Program Files%\OpenIt\Open It!""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
DisplayIcon = ""%Program Files%\OpenIt\Open It!\openit.exe""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
Publisher = "OpenIt"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
URLUpdateInfo = "{UPDATEURL}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
URLInfoAbout = "{ABOUTURL}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
DisplayVersion = "1.1.1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
VersionMajor = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
VersionMinor = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
NoModify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
NoRepair = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
EstimatedSize = "16233"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
OpenIt Open It!
HelpLink = "{HELPURL}"

Other Details

This potentially unwanted application connects to the following possibly malicious URL:

  • http://cdn.{BLOCKED}atform.com/scripts/1/adnl.min.js
  • http://cdneu.{BLOCKED}lzipextractorapp.com/app/Cmp/openit.cis
  • http://cdnus.{BLOCKED}lzipextractorapp.com/app/Cmp/openit.cis
  • http://d.{BLOCKED}atform.com/api/vv/1?callback={value}&ts={value}&sessionId={value}&rfr={value}&siteId={value}&aus={value}
  • http://os-test.{BLOCKED}lzipextractorapp.com/CM_FL_7/?v={value}&c={value}
  • http://os2.{BLOCKED}lzipextractorapp.com/CM_FL_7/?v={value}&c={value}
  • http://rp.{BLOCKED}lzipextractorapp.com/?pcrc={value}
  • http://www.{BLOCKED}lzipextractorapp.com/gb/welcome/?sr={value}&lp={value}&tschnl={value}&c={value}

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 1.809.00
SSAPI PATTERN Date: 09 Feb 2017

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

Identify and terminate files detected as PUA_INSTALLCORE.GK

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

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
    • OpenIt Open It!

Step 5

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%\is{random}
  • %All Users Profile%\Start Menu\Programs\Open It!
  • %Program Files%\OpenIt
  • %Program Files%\OpenIt\Open It!

Step 6

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%\{random filename}.log
  • %User Temp%\ns{random}.tmp
  • %Desktop%\Open It!.lnk

Step 7

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