PUA_INSTALLCORE.GS

April 24, 2018

Analysis by: Michael Jay Villanueva

ALIASES:

PUP.Optional.InstallCore (Malwarebytes); Riskware/InstallCore (Fortinet); AdWare.Win32.DealPly.cylfj (Kaspersky)

PLATFORM:

Windows

OVERALL RISK RATING:

DAMAGE POTENTIAL:

DISTRIBUTION POTENTIAL:

REPORTED INFECTION:

INFORMATION EXPOSURE:

Threat Type: Potentially Unwanted Application
Destructiveness: No
Encrypted: No
In the wild: Yes

OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

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 arrives as a component bundled with malware/grayware packages.

It does not have any propagation routine.

It does not have any backdoor routine.

It modifies the Internet Explorer Zone Settings.

It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible.

TECHNICAL DETAILS

File Size:

1,542,472 bytes

File Type:

EXE

Memory Resident:

Initial Samples Received Date:

15 Jan 2018

Payload:

Drops files, Connects to URLs/IPs

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.

It arrives as a component bundled with malware/grayware packages.

Installation

This Potentially Unwanted Application drops the following files:

%User Temp%\{random filename}.log
%User Temp%\in{random characters}\csshover3.htc
%User Temp%\in{random characters}\form.bmp.Mask
%User Temp%\in{random characters}\css\ie6_main.css
%User Temp%\in{random characters}\css\ie6_main.scss
%User Temp%\in{random characters}\css\main.css
%User Temp%\in{random characters}\css\main.scss
%User Temp%\in{random characters}\css\_functions.scss
%User Temp%\in{random characters}\css\_helpers.scss
%User Temp%\in{random characters}\css\_variables.scss
%User Temp%\in{random characters}\css\helpers\_align.scss
%User Temp%\in{random characters}\css\helpers\_backgrounds.scss
%User Temp%\in{random characters}\css\helpers\_border-radius.scss
%User Temp%\in{random characters}\css\helpers\_border.scss
%User Temp%\in{random characters}\css\helpers\_clearfix.scss
%User Temp%\in{random characters}\css\helpers\_colors.scss
%User Temp%\in{random characters}\css\helpers\_display.scss
%User Temp%\in{random characters}\css\helpers\_float.scss
%User Temp%\in{random characters}\css\helpers\_lists.scss
%User Temp%\in{random characters}\css\helpers\_margin.scss
%User Temp%\in{random characters}\css\helpers\_padding.scss
%User Temp%\in{random characters}\css\helpers\_positions.scss
%User Temp%\in{random characters}\css\helpers\_typography.scss
%User Temp%\in{random characters}\css\helpers\_visibility.scss
%User Temp%\in{random characters}\css\helpers\_width-height.scss
%User Temp%\in{random characters}\css\helpers\_z-index.scss
%User Temp%\in{random characters}\css\sdk-ui\_browse.scss
%User Temp%\in{random characters}\css\sdk-ui\_button.scss
%User Temp%\in{random characters}\css\sdk-ui\_checkbox.scss
%User Temp%\in{random characters}\css\sdk-ui\_progress-bar.scss
%User Temp%\in{random characters}\css\sdk-ui\images\button-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg-corner.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg2.png
%User Temp%\in{random characters}\images\BG.png
%User Temp%\in{random characters}\images\Close.png
%User Temp%\in{random characters}\images\Close_Hover.png
%User Temp%\in{random characters}\images\Color_Button.png
%User Temp%\in{random characters}\images\Color_Button_Hover.png
%User Temp%\in{random characters}\images\Grey_Button.png
%User Temp%\in{random characters}\images\Grey_Button_Hover.png
%User Temp%\in{random characters}\images\Icon_Generic.png
%User Temp%\in{random characters}\images\Loader.gif
%User Temp%\in{random characters}\images\Pause_Button.png
%User Temp%\in{random characters}\images\Progress.png
%User Temp%\in{random characters}\images\ProgressBar.png
%User Temp%\in{random characters}\images\Quick_Specs.png
%User Temp%\in{random characters}\images\Resume_Button.png
%User Temp%\in{random characters}\images\sponsored.png
%User Temp%\in{random characters}\locale\CS.locale
%User Temp%\in{random characters}\locale\DE.locale
%User Temp%\in{random characters}\locale\EL.locale
%User Temp%\in{random characters}\locale\EN.locale
%User Temp%\in{random characters}\locale\ES.locale
%User Temp%\in{random characters}\locale\FR.locale
%User Temp%\in{random characters}\locale\ID.locale
%User Temp%\in{random characters}\locale\IT.locale
%User Temp%\in{random characters}\locale\JA.locale
%User Temp%\in{random characters}\locale\NL.locale
%User Temp%\in{random characters}\locale\PL.locale
%User Temp%\in{random characters}\locale\PT.locale
%User Temp%\in{random characters}\locale\RU.locale
%User Temp%\in{random characters}\locale\TR.locale
%User Temp%\in{random characters}\{random filename}.tmp
%User Temp%\in{random characters}\bootstrap_{random}.html

(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.)

It adds the following processes:

{Malware Path}\{Malware Filename}.exe /_ShowProgress /mnl

It creates the following folders:

%User Temp%\in{random characters}\css
%User Temp%\in{random characters}\css\helpers
%User Temp%\in{random characters}\css\sdk-ui
%User Temp%\in{random characters}\css\sdk-ui\images
%User Temp%\in{random characters}\images
%User Temp%\in{random characters}\locale

Propagation

This Potentially Unwanted Application does not have any propagation routine.

Backdoor Routine

This Potentially Unwanted Application does not have any backdoor routine.

Rootkit Capabilities

This Potentially Unwanted Application does not have rootkit capabilities.

Web Browser Home Page and Search Page Modification

This Potentially Unwanted Application modifies the Internet Explorer Zone Settings.

Other Details

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

http://rp.{BLOCKED}iverystock.com/
http://os.{BLOCKED}iverystock.com/DownloadAstro/

However, as of this writing, the said sites are inaccessible.

It does not exploit any vulnerability.

NOTES:

This PUA shows the following progress bar once executed:

A message box will appear, saying that a product configuration is missing:

SOLUTION

Minimum Scan Engine:

9.850

SSAPI PATTERN File:

1.911.00

SSAPI PATTERN Date:

18 Jan 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

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 characters}\css
%User Temp%\in{random characters}\css\helpers
%User Temp%\in{random characters}\css\sdk-ui
%User Temp%\in{random characters}\css\sdk-ui\images
%User Temp%\in{random characters}\images
%User Temp%\in{random characters}\locale

To delete malware/grayware/spyware folders:

For Windows 2000, Windows XP, and Windows Server 2003:

Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
In the File name* input box, type:

%User Temp%\in{random characters}\css
%User Temp%\in{random characters}\css\helpers
%User Temp%\in{random characters}\css\sdk-ui
%User Temp%\in{random characters}\css\sdk-ui\images
%User Temp%\in{random characters}\images
%User Temp%\in{random characters}\locale
In the Look In drop-down list, select My Computer, then press Enter.
Once located, select the folder then press SHIFT+DELETE to permanently delete the folder.
Repeat steps 2 to 4 for the remaining folders: %User Temp%\in{random characters}\css
%User Temp%\in{random characters}\css\helpers
%User Temp%\in{random characters}\css\sdk-ui
%User Temp%\in{random characters}\css\sdk-ui\images
%User Temp%\in{random characters}\images
%User Temp%\in{random characters}\locale

*Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
In the Search Computer/This PC input box, type:
%User Temp%\in{random characters}\css
%User Temp%\in{random characters}\css\helpers
%User Temp%\in{random characters}\css\sdk-ui
%User Temp%\in{random characters}\css\sdk-ui\images
%User Temp%\in{random characters}\images
%User Temp%\in{random characters}\locale
Once located, select the file then press SHIFT+DELETE to permanently delete the folder.
Repeat steps 2-3 for the remaining folders: %User Temp%\in{random characters}\css
%User Temp%\in{random characters}\css\helpers
%User Temp%\in{random characters}\css\sdk-ui
%User Temp%\in{random characters}\css\sdk-ui\images
%User Temp%\in{random characters}\images
%User Temp%\in{random characters}\locale

*Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 4

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%\in{random characters}\csshover3.htc
%User Temp%\in{random characters}\form.bmp.Mask
%User Temp%\in{random characters}\css\ie6_main.css
%User Temp%\in{random characters}\css\ie6_main.scss
%User Temp%\in{random characters}\css\main.css
%User Temp%\in{random characters}\css\main.scss
%User Temp%\in{random characters}\css\_functions.scss
%User Temp%\in{random characters}\css\_helpers.scss
%User Temp%\in{random characters}\css\_variables.scss
%User Temp%\in{random characters}\css\helpers\_align.scss
%User Temp%\in{random characters}\css\helpers\_backgrounds.scss
%User Temp%\in{random characters}\css\helpers\_border-radius.scss
%User Temp%\in{random characters}\css\helpers\_border.scss
%User Temp%\in{random characters}\css\helpers\_clearfix.scss
%User Temp%\in{random characters}\css\helpers\_colors.scss
%User Temp%\in{random characters}\css\helpers\_display.scss
%User Temp%\in{random characters}\css\helpers\_float.scss
%User Temp%\in{random characters}\css\helpers\_lists.scss
%User Temp%\in{random characters}\css\helpers\_margin.scss
%User Temp%\in{random characters}\css\helpers\_padding.scss
%User Temp%\in{random characters}\css\helpers\_positions.scss
%User Temp%\in{random characters}\css\helpers\_typography.scss
%User Temp%\in{random characters}\css\helpers\_visibility.scss
%User Temp%\in{random characters}\css\helpers\_width-height.scss
%User Temp%\in{random characters}\css\helpers\_z-index.scss
%User Temp%\in{random characters}\css\sdk-ui\_browse.scss
%User Temp%\in{random characters}\css\sdk-ui\_button.scss
%User Temp%\in{random characters}\css\sdk-ui\_checkbox.scss
%User Temp%\in{random characters}\css\sdk-ui\_progress-bar.scss
%User Temp%\in{random characters}\css\sdk-ui\images\button-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg-corner.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg2.png
%User Temp%\in{random characters}\images\BG.png
%User Temp%\in{random characters}\images\Close.png
%User Temp%\in{random characters}\images\Close_Hover.png
%User Temp%\in{random characters}\images\Color_Button.png
%User Temp%\in{random characters}\images\Color_Button_Hover.png
%User Temp%\in{random characters}\images\Grey_Button.png
%User Temp%\in{random characters}\images\Grey_Button_Hover.png
%User Temp%\in{random characters}\images\Icon_Generic.png
%User Temp%\in{random characters}\images\Loader.gif
%User Temp%\in{random characters}\images\Pause_Button.png
%User Temp%\in{random characters}\images\Progress.png
%User Temp%\in{random characters}\images\ProgressBar.png
%User Temp%\in{random characters}\images\Quick_Specs.png
%User Temp%\in{random characters}\images\Resume_Button.png
%User Temp%\in{random characters}\images\sponsored.png
%User Temp%\in{random characters}\locale\CS.locale
%User Temp%\in{random characters}\locale\DE.locale
%User Temp%\in{random characters}\locale\EL.locale
%User Temp%\in{random characters}\locale\EN.locale
%User Temp%\in{random characters}\locale\ES.locale
%User Temp%\in{random characters}\locale\FR.locale
%User Temp%\in{random characters}\locale\ID.locale
%User Temp%\in{random characters}\locale\IT.locale
%User Temp%\in{random characters}\locale\JA.locale
%User Temp%\in{random characters}\locale\NL.locale
%User Temp%\in{random characters}\locale\PL.locale
%User Temp%\in{random characters}\locale\PT.locale
%User Temp%\in{random characters}\locale\RU.locale
%User Temp%\in{random characters}\locale\TR.locale
%User Temp%\in{random characters}\{random filename}.tmp
%User Temp%\in{random characters}\bootstrap_{random}.html

To manually delete a malware/grayware file from an affected system:

• For Windows 2000, Windows XP, and Windows Server 2003:

Right-click Start then click Search....
In the File name* input box, type the following:
%User Temp%\{random filename}.log
%User Temp%\in{random characters}\csshover3.htc
%User Temp%\in{random characters}\form.bmp.Mask
%User Temp%\in{random characters}\css\ie6_main.css
%User Temp%\in{random characters}\css\ie6_main.scss
%User Temp%\in{random characters}\css\main.css
%User Temp%\in{random characters}\css\main.scss
%User Temp%\in{random characters}\css\_functions.scss
%User Temp%\in{random characters}\css\_helpers.scss
%User Temp%\in{random characters}\css\_variables.scss
%User Temp%\in{random characters}\css\helpers\_align.scss
%User Temp%\in{random characters}\css\helpers\_backgrounds.scss
%User Temp%\in{random characters}\css\helpers\_border-radius.scss
%User Temp%\in{random characters}\css\helpers\_border.scss
%User Temp%\in{random characters}\css\helpers\_clearfix.scss
%User Temp%\in{random characters}\css\helpers\_colors.scss
%User Temp%\in{random characters}\css\helpers\_display.scss
%User Temp%\in{random characters}\css\helpers\_float.scss
%User Temp%\in{random characters}\css\helpers\_lists.scss
%User Temp%\in{random characters}\css\helpers\_margin.scss
%User Temp%\in{random characters}\css\helpers\_padding.scss
%User Temp%\in{random characters}\css\helpers\_positions.scss
%User Temp%\in{random characters}\css\helpers\_typography.scss
%User Temp%\in{random characters}\css\helpers\_visibility.scss
%User Temp%\in{random characters}\css\helpers\_width-height.scss
%User Temp%\in{random characters}\css\helpers\_z-index.scss
%User Temp%\in{random characters}\css\sdk-ui\_browse.scss
%User Temp%\in{random characters}\css\sdk-ui\_button.scss
%User Temp%\in{random characters}\css\sdk-ui\_checkbox.scss
%User Temp%\in{random characters}\css\sdk-ui\_progress-bar.scss
%User Temp%\in{random characters}\css\sdk-ui\images\button-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg-corner.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg2.png
%User Temp%\in{random characters}\images\BG.png
%User Temp%\in{random characters}\images\Close.png
%User Temp%\in{random characters}\images\Close_Hover.png
%User Temp%\in{random characters}\images\Color_Button.png
%User Temp%\in{random characters}\images\Color_Button_Hover.png
%User Temp%\in{random characters}\images\Grey_Button.png
%User Temp%\in{random characters}\images\Grey_Button_Hover.png
%User Temp%\in{random characters}\images\Icon_Generic.png
%User Temp%\in{random characters}\images\Loader.gif
%User Temp%\in{random characters}\images\Pause_Button.png
%User Temp%\in{random characters}\images\Progress.png
%User Temp%\in{random characters}\images\ProgressBar.png
%User Temp%\in{random characters}\images\Quick_Specs.png
%User Temp%\in{random characters}\images\Resume_Button.png
%User Temp%\in{random characters}\images\sponsored.png
%User Temp%\in{random characters}\locale\CS.locale
%User Temp%\in{random characters}\locale\DE.locale
%User Temp%\in{random characters}\locale\EL.locale
%User Temp%\in{random characters}\locale\EN.locale
%User Temp%\in{random characters}\locale\ES.locale
%User Temp%\in{random characters}\locale\FR.locale
%User Temp%\in{random characters}\locale\ID.locale
%User Temp%\in{random characters}\locale\IT.locale
%User Temp%\in{random characters}\locale\JA.locale
%User Temp%\in{random characters}\locale\NL.locale
%User Temp%\in{random characters}\locale\PL.locale
%User Temp%\in{random characters}\locale\PT.locale
%User Temp%\in{random characters}\locale\RU.locale
%User Temp%\in{random characters}\locale\TR.locale
%User Temp%\in{random characters}\{random filename}.tmp
%User Temp%\in{random characters}\bootstrap_{random}.html
In the Look In drop-down list, select My Computer then press Enter.
Once located, select the file then press SHIFT+DELETE to delete it.
*Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).

• For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
In the Search Computer/This PC input box, type:
%User Temp%\{random filename}.log
%User Temp%\in{random characters}\csshover3.htc
%User Temp%\in{random characters}\form.bmp.Mask
%User Temp%\in{random characters}\css\ie6_main.css
%User Temp%\in{random characters}\css\ie6_main.scss
%User Temp%\in{random characters}\css\main.css
%User Temp%\in{random characters}\css\main.scss
%User Temp%\in{random characters}\css\_functions.scss
%User Temp%\in{random characters}\css\_helpers.scss
%User Temp%\in{random characters}\css\_variables.scss
%User Temp%\in{random characters}\css\helpers\_align.scss
%User Temp%\in{random characters}\css\helpers\_backgrounds.scss
%User Temp%\in{random characters}\css\helpers\_border-radius.scss
%User Temp%\in{random characters}\css\helpers\_border.scss
%User Temp%\in{random characters}\css\helpers\_clearfix.scss
%User Temp%\in{random characters}\css\helpers\_colors.scss
%User Temp%\in{random characters}\css\helpers\_display.scss
%User Temp%\in{random characters}\css\helpers\_float.scss
%User Temp%\in{random characters}\css\helpers\_lists.scss
%User Temp%\in{random characters}\css\helpers\_margin.scss
%User Temp%\in{random characters}\css\helpers\_padding.scss
%User Temp%\in{random characters}\css\helpers\_positions.scss
%User Temp%\in{random characters}\css\helpers\_typography.scss
%User Temp%\in{random characters}\css\helpers\_visibility.scss
%User Temp%\in{random characters}\css\helpers\_width-height.scss
%User Temp%\in{random characters}\css\helpers\_z-index.scss
%User Temp%\in{random characters}\css\sdk-ui\_browse.scss
%User Temp%\in{random characters}\css\sdk-ui\_button.scss
%User Temp%\in{random characters}\css\sdk-ui\_checkbox.scss
%User Temp%\in{random characters}\css\sdk-ui\_progress-bar.scss
%User Temp%\in{random characters}\css\sdk-ui\images\button-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg-corner.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg.png
%User Temp%\in{random characters}\css\sdk-ui\images\progress-bg2.png
%User Temp%\in{random characters}\images\BG.png
%User Temp%\in{random characters}\images\Close.png
%User Temp%\in{random characters}\images\Close_Hover.png
%User Temp%\in{random characters}\images\Color_Button.png
%User Temp%\in{random characters}\images\Color_Button_Hover.png
%User Temp%\in{random characters}\images\Grey_Button.png
%User Temp%\in{random characters}\images\Grey_Button_Hover.png
%User Temp%\in{random characters}\images\Icon_Generic.png
%User Temp%\in{random characters}\images\Loader.gif
%User Temp%\in{random characters}\images\Pause_Button.png
%User Temp%\in{random characters}\images\Progress.png
%User Temp%\in{random characters}\images\ProgressBar.png
%User Temp%\in{random characters}\images\Quick_Specs.png
%User Temp%\in{random characters}\images\Resume_Button.png
%User Temp%\in{random characters}\images\sponsored.png
%User Temp%\in{random characters}\locale\CS.locale
%User Temp%\in{random characters}\locale\DE.locale
%User Temp%\in{random characters}\locale\EL.locale
%User Temp%\in{random characters}\locale\EN.locale
%User Temp%\in{random characters}\locale\ES.locale
%User Temp%\in{random characters}\locale\FR.locale
%User Temp%\in{random characters}\locale\ID.locale
%User Temp%\in{random characters}\locale\IT.locale
%User Temp%\in{random characters}\locale\JA.locale
%User Temp%\in{random characters}\locale\NL.locale
%User Temp%\in{random characters}\locale\PL.locale
%User Temp%\in{random characters}\locale\PT.locale
%User Temp%\in{random characters}\locale\RU.locale
%User Temp%\in{random characters}\locale\TR.locale
%User Temp%\in{random characters}\{random filename}.tmp
%User Temp%\in{random characters}\bootstrap_{random}.html
Once located, select the file then press SHIFT+DELETE to delete it.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 5

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

Step 6

Reset Internet security settings

[ Learn More ]

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PUA_INSTALLCORE.GS

OVERVIEW

TECHNICAL DETAILS

SOLUTION

Resources

Support

About Trend

Country Headquarters

PUA_INSTALLCORE.GS

OVERVIEW

TECHNICAL DETAILS

SOLUTION

Resources

Support

About Trend

Country Headquarters

The Americas

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Europe

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