Analysis by: Pearl Charlaine Espejo

ALIASES:

PUP/DownloadAssistant (Panda); PUP.InstallCore/Variant (SUPERAntiSpyware); PUP.Optional.InstallCore (Malwarebytes); GrayWare[Adware]/Win32.InstallCore.gena (Antiy-AVL)

 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: 1,189,944 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 06 Oct 2016

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:

  • %Desktop%\Continue Flash Player Pro Installation.lnk
  • %User Temp%\ICReinstall_{PUA filename}.exe
  • %User Temp%\{random filename}.log
  • %User Temp%\in{random 1}\css\_functions.scss
  • %User Temp%\in{random 1}\css\_helpers.scss
  • %User Temp%\in{random 1}\css\_variables.scss
  • %User Temp%\in{random 1}\css\helpers\_align.scss
  • %User Temp%\in{random 1}\css\helpers\_backgrounds.scss
  • %User Temp%\in{random 1}\css\helpers\_border-radius.scss
  • %User Temp%\in{random 1}\css\helpers\_border.scss
  • %User Temp%\in{random 1}\css\helpers\_clearfix.scss
  • %User Temp%\in{random 1}\css\helpers\_colors.scss
  • %User Temp%\in{random 1}\css\helpers\_display.scss
  • %User Temp%\in{random 1}\css\helpers\_float.scss
  • %User Temp%\in{random 1}\css\helpers\_lists.scss
  • %User Temp%\in{random 1}\css\helpers\_margin.scss
  • %User Temp%\in{random 1}\css\helpers\_padding.scss
  • %User Temp%\in{random 1}\css\helpers\_positions.scss
  • %User Temp%\in{random 1}\css\helpers\_typography.scss
  • %User Temp%\in{random 1}\css\helpers\_visibility.scss
  • %User Temp%\in{random 1}\css\helpers\_width-height.scss
  • %User Temp%\in{random 1}\css\helpers\_z-index.scss
  • %User Temp%\in{random 1}\css\ie6_main.css
  • %User Temp%\in{random 1}\css\ie6_main.scss
  • %User Temp%\in{random 1}\css\main.css
  • %User Temp%\in{random 1}\css\main.css.map
  • %User Temp%\in{random 1}\css\main.scss
  • %User Temp%\in{random 1}\css\main_manual.css
  • %User Temp%\in{random 1}\css\main_manual.css.map
  • %User Temp%\in{random 1}\css\main_manual.scss
  • %User Temp%\in{random 1}\css\sdk-ui\_browse.scss
  • %User Temp%\in{random 1}\css\sdk-ui\_button.scss
  • %User Temp%\in{random 1}\css\sdk-ui\_checkbox.scss
  • %User Temp%\in{random 1}\css\sdk-ui\_progress-bar.scss
  • %User Temp%\in{random 1}\css\sdk-ui\images\button-bg.png
  • %User Temp%\in{random 1}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\in{random 1}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\in{random 1}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\in{random 1}\csshover3.htc
  • %User Temp%\in{random 1}\form.bmp.Mask
  • %User Temp%\in{random 1}\images\BG.jpg
  • %User Temp%\in{random 1}\images\BG.png
  • %User Temp%\in{random 1}\images\Close.png
  • %User Temp%\in{random 1}\images\Close_Hover.png
  • %User Temp%\in{random 1}\images\Color_Button.png
  • %User Temp%\in{random 1}\images\Color_Button_Hover.png
  • %User Temp%\in{random 1}\images\Grey_Button.png
  • %User Temp%\in{random 1}\images\Grey_Button_Hover.png
  • %User Temp%\in{random 1}\images\Icon_Generic.png
  • %User Temp%\in{random 1}\images\Loader.gif
  • %User Temp%\in{random 1}\images\Pause_Button.png
  • %User Temp%\in{random 1}\images\Progress.png
  • %User Temp%\in{random 1}\images\ProgressBar.png
  • %User Temp%\in{random 1}\images\Quick_Specs.png
  • %User Temp%\in{random 1}\images\Resume_Button.png
  • %User Temp%\in{random 1}\images\sponsored.png
  • %User Temp%\in{random 1}\locale\CS.locale
  • %User Temp%\in{random 1}\locale\DA.locale
  • %User Temp%\in{random 1}\locale\DE.locale
  • %User Temp%\in{random 1}\locale\EL.locale
  • %User Temp%\in{random 1}\locale\EN.locale
  • %User Temp%\in{random 1}\locale\ES.locale
  • %User Temp%\in{random 1}\locale\FI.locale
  • %User Temp%\in{random 1}\locale\FR.locale
  • %User Temp%\in{random 1}\locale\ID.locale
  • %User Temp%\in{random 1}\locale\IT.locale
  • %User Temp%\in{random 1}\locale\JA.locale
  • %User Temp%\in{random 1}\locale\KO.locale
  • %User Temp%\in{random 1}\locale\NL.locale
  • %User Temp%\in{random 1}\locale\NO.locale
  • %User Temp%\in{random 1}\locale\PL.locale
  • %User Temp%\in{random 1}\locale\PT.locale
  • %User Temp%\in{random 1}\locale\RU.locale
  • %User Temp%\in{random 1}\locale\SV.locale
  • %User Temp%\in{random 1}\locale\TR.locale
  • %User Temp%\in{random 1}\locale\ZH.locale
  • %User Temp%\in{random 2}\bootstrap_35704.html
  • %User Temp%\in{random 2}\css\helpers\_align.scss
  • %User Temp%\in{random 2}\css\helpers\_backgrounds.scss
  • %User Temp%\in{random 2}\css\helpers\_border-radius.scss
  • %User Temp%\in{random 2}\css\helpers\_border.scss
  • %User Temp%\in{random 2}\css\helpers\_clearfix.scss
  • %User Temp%\in{random 2}\css\helpers\_colors.scss
  • %User Temp%\in{random 2}\css\helpers\_display.scss
  • %User Temp%\in{random 2}\css\helpers\_float.scss
  • %User Temp%\in{random 2}\css\helpers\_lists.scss
  • %User Temp%\in{random 2}\css\helpers\_margin.scss
  • %User Temp%\in{random 2}\css\helpers\_padding.scss
  • %User Temp%\in{random 2}\css\helpers\_positions.scss
  • %User Temp%\in{random 2}\css\helpers\_typography.scss
  • %User Temp%\in{random 2}\css\helpers\_visibility.scss
  • %User Temp%\in{random 2}\css\helpers\_width-height.scss
  • %User Temp%\in{random 2}\css\helpers\_z-index.scss
  • %User Temp%\in{random 2}\css\ie6_main.css
  • %User Temp%\in{random 2}\css\ie6_main.scss
  • %User Temp%\in{random 2}\css\main.css
  • %User Temp%\in{random 3}\{random characters}_stp.EXE
  • %User Temp%\in{random 3}\{random characters}.tmp

(Note: %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.. %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.)

It creates the following folders:

  • %User Temp%\in{random 1}
  • %User Temp%\in{random 2}
  • %User Temp%\in{random 3}

(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.)

Other System Modifications

This potentially unwanted application adds the following registry keys:

HKEY_CURRENT_USER\Software\undefined

It adds the following registry entries:

HKEY_CURRENT_USER\Software\undefined
FlashPlayerPro.exe = "{numbers},http://d1h8ctfgn173yl.cloudfront.net/carrier/MediaPlayAir.exe"

Download Routine

This potentially unwanted application saves the files it downloads using the following names:

  • %User Profile%\Downloads\FlashPlayerPro.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other Details

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

  • http://os.{BLOCKED}rada.com/MEDIA_MARMAR_IE/?v={value}&c={value}&t={value}
  • http://rp.{BLOCKED}rada.com/?v={value}&subver={value}&pcrc={value}
  • http://info.{BLOCKED}rada.com/?v={value}&c={value}&at={value}&cntr={value}
  • http://d1h8ctfgn173yl.{BLOCKED}ront.net/carrier/banner_fp.jpg
  • http://{BLOCKED}a.space/pages/MMMedia/MarMar_TYP.html
  • http://{BLOCKED}a.space/pages/MMMedia/css/style.css
  • http://d1h8ctfgn173yl.{BLOCKED}ront.net/carrier/MediaPlayAir.exe

  SOLUTION

Minimum Scan Engine: 9.800
SSAPI PATTERN File: 1.777.00
SSAPI PATTERN Date: 20 Oct 2016

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.GF

[ 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_CURRENT_USER\Software
    • undefined

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%\in{random 1}
  • %User Temp%\in{random 2}
  • %User Temp%\in{random 3}

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 Profile%\Downloads\FlashPlayerPro.exe
  • %Desktop%\Continue Flash Player Pro Installation.lnk
  • %User Temp%\ICReinstall_{PUA filename}.exe
  • %User Temp%\{random filename}.log

Step 7

Scan your computer with your Trend Micro product to delete files detected as PUA_InstallCore.GF. 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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