Adware.Win32.Installcore.R002C0RCE25

April 10, 2025
 Analysis by: Neljorn Nathaniel Aguas
 ALIASES:

Win32/InstallCore.Gen.A potentially unwanted application (NOD32)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

This Adware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

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

  TECHNICAL DETAILS

File Size:

969,402 bytes

File Type:

EXE

Initial Samples Received Date:

18 Mar 2025

Payload:

Connects to URLs/IPs, Drops files, Modifies system registry, Creates files

Arrival Details

This Adware 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 Adware drops the following files:

  • Deleted upon process termination:
    • %User Temp%\{Random Number}.log
    • %User Temp%\inH{Random Number}\css\ie6_Dlm_main.css
    • %User Temp%\inH{Random Number}\css\mainDlm.css
    • %User Temp%\inH{Random Number}\css\sdk-ui\browse.css
    • %User Temp%\inH{Random Number}\css\sdk-ui\button.css
    • %User Temp%\inH{Random Number}\css\sdk-ui\checkbox.css
    • %User Temp%\inH{Random Number}\css\sdk-ui\images\button-bg.png
    • %User Temp%\inH{Random Number}\css\sdk-ui\images\progress-bg-corner.png
    • %User Temp%\inH{Random Number}\css\sdk-ui\images\progress-bg.png
    • %User Temp%\inH{Random Number}\css\sdk-ui\images\progress-bg2.png
    • %User Temp%\inH{Random Number}\css\sdk-ui\progress-bar.css
    • %User Temp%\inH{Random Number}\csshover3.htc
    • %User Temp%\inH{Random Number}\form.bmp.Mask
    • %User Temp%\inH{Random Number}\images\BGD.png
    • %User Temp%\inH{Random Number}\images\Close.png
    • %User Temp%\inH{Random Number}\images\Close_Hover.png
    • %User Temp%\inH{Random Number}\images\Color_Button.png
    • %User Temp%\inH{Random Number}\images\Color_Button_Hover.png
    • %User Temp%\inH{Random Number}\images\Grey_Button.png
    • %User Temp%\inH{Random Number}\images\Grey_Button_Hover.png
    • %User Temp%\inH{Random Number}\images\Icon_Generic.png
    • %User Temp%\inH{Random Number}\images\Loader.gif
    • %User Temp%\inH{Random Number}\images\Pause_Button.png
    • %User Temp%\inH{Random Number}\images\ProgressBarD.png
    • %User Temp%\inH{Random Number}\images\ProgressD.png
    • %User Temp%\inH{Random Number}\images\Quick_Specs.png
    • %User Temp%\inH{Random Number}\images\Resume_Button.png
    • %User Temp%\inH{Random Number}\images\sponsored.png
    • %User Temp%\inH{Random Number}\locale\DLM\CS.locale
    • %User Temp%\inH{Random Number}\locale\DLM\DA.locale
    • %User Temp%\inH{Random Number}\locale\DLM\DE.locale
    • %User Temp%\inH{Random Number}\locale\DLM\EL.locale
    • %User Temp%\inH{Random Number}\locale\DLM\EN.locale
    • %User Temp%\inH{Random Number}\locale\DLM\ES.locale
    • %User Temp%\inH{Random Number}\locale\DLM\FI.locale
    • %User Temp%\inH{Random Number}\locale\DLM\FR.locale
    • %User Temp%\inH{Random Number}\locale\DLM\ID.locale
    • %User Temp%\inH{Random Number}\locale\DLM\IT.locale
    • %User Temp%\inH{Random Number}\locale\DLM\JA.locale
    • %User Temp%\inH{Random Number}\locale\DLM\KO.locale
    • %User Temp%\inH{Random Number}\locale\DLM\NL.locale
    • %User Temp%\inH{Random Number}\locale\DLM\NO.locale
    • %User Temp%\inH{Random Number}\locale\DLM\PL.locale
    • %User Temp%\inH{Random Number}\locale\DLM\PT.locale
    • %User Temp%\inH{Random Number}\locale\DLM\RU.locale
    • %User Temp%\inH{Random Number}\locale\DLM\SV.locale
    • %User Temp%\inH{Random Number}\locale\DLM\TR.locale
    • %User Temp%\inH{Random Number}\locale\DLM\ZH.locale
    • %User Temp%\inH{Random Number}\bootstrap_4976.html
    • %User Temp%\in{Random Hex}\{Random Hex}.tmp
    • %User Temp%\{Random Number}.log
    • %User Temp%\{Random Hex}.log

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • "{Grayware Path}\{Grayware Filename}" /_ShowProgress /PrTxt:TG9hZGluZy4uLg==

It creates the following folders:

  • Deleted upon process termination:
    • %User Temp%\inH{Random Number}
    • %User Temp%\inH{Random Number}\css
    • %User Temp%\inH{Random Number}\css\sdk-ui
    • %User Temp%\inH{Random Number}\css\sdk-ui\images
    • %User Temp%\inH{Random Number}\images
    • %User Temp%\inH{Random Number}\locale
    • %User Temp%\inH{Random Number}\locale\DLM
    • %User Temp%\in{Random Hex}

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other System Modifications

This Adware adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = {Grayware Filename}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = {Random Number}

Other Details

This Adware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication

It connects to the following possibly malicious URL:

  • http://{BLOCKED}ironito2.com/?v=2.0&subver=6.21&pcrc={Random Integer}
  • http://{BLOCKED}ronito2.com/?v=2.0&subver=6.21&pcrc={Random Integer}
  • http://{BLOCKED}bironito2.com/?v=1.03&c={Random Hex}&at={Random Integer}&cntr=1
  • http://{BLOCKED}bironito2.com/?v=1.03&c={Random Hex}&at={Random Integer}&cntr=2
  • http://{BLOCKEDronito2.com/Bidmonitor/?v=6.0&c={Random Integer}&t={Random Integer}

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

  SOLUTION

Minimum Scan Engine:

9.800

SSAPI PATTERN File:

2.821.00

SSAPI PATTERN Date:

27 Mar 2025

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • Name = {Grayware Filename}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • ID = {Random Number}

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\DirectDraw
    • MostRecentApplication

Step 5

Search and delete these files

[ 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 Number}.log
  • %User Temp%\inH{Random Number}\css\ie6_Dlm_main.css
  • %User Temp%\inH{Random Number}\css\mainDlm.css
  • %User Temp%\inH{Random Number}\css\sdk-ui\browse.css
  • %User Temp%\inH{Random Number}\css\sdk-ui\button.css
  • %User Temp%\inH{Random Number}\css\sdk-ui\checkbox.css
  • %User Temp%\inH{Random Number}\css\sdk-ui\images\button-bg.png
  • %User Temp%\inH{Random Number}\css\sdk-ui\images\progress-bg-corner.png
  • %User Temp%\inH{Random Number}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\inH{Random Number}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\inH{Random Number}\css\sdk-ui\progress-bar.css
  • %User Temp%\inH{Random Number}\csshover3.htc
  • %User Temp%\inH{Random Number}\form.bmp.Mask
  • %User Temp%\inH{Random Number}\images\BGD.png
  • %User Temp%\inH{Random Number}\images\Close.png
  • %User Temp%\inH{Random Number}\images\Close_Hover.png
  • %User Temp%\inH{Random Number}\images\Color_Button.png
  • %User Temp%\inH{Random Number}\images\Color_Button_Hover.png
  • %User Temp%\inH{Random Number}\images\Grey_Button.png
  • %User Temp%\inH{Random Number}\images\Grey_Button_Hover.png
  • %User Temp%\inH{Random Number}\images\Icon_Generic.png
  • %User Temp%\inH{Random Number}\images\Loader.gif
  • %User Temp%\inH{Random Number}\images\Pause_Button.png
  • %User Temp%\inH{Random Number}\images\ProgressBarD.png
  • %User Temp%\inH{Random Number}\images\ProgressD.png
  • %User Temp%\inH{Random Number}\images\Quick_Specs.png
  • %User Temp%\inH{Random Number}\images\Resume_Button.png
  • %User Temp%\inH{Random Number}\images\sponsored.png
  • %User Temp%\inH{Random Number}\locale\DLM\CS.locale
  • %User Temp%\inH{Random Number}\locale\DLM\DA.locale
  • %User Temp%\inH{Random Number}\locale\DLM\DE.locale
  • %User Temp%\inH{Random Number}\locale\DLM\EL.locale
  • %User Temp%\inH{Random Number}\locale\DLM\EN.locale
  • %User Temp%\inH{Random Number}\locale\DLM\ES.locale
  • %User Temp%\inH{Random Number}\locale\DLM\FI.locale
  • %User Temp%\inH{Random Number}\locale\DLM\FR.locale
  • %User Temp%\inH{Random Number}\locale\DLM\ID.locale
  • %User Temp%\inH{Random Number}\locale\DLM\IT.locale
  • %User Temp%\inH{Random Number}\locale\DLM\JA.locale
  • %User Temp%\inH{Random Number}\locale\DLM\KO.locale
  • %User Temp%\inH{Random Number}\locale\DLM\NL.locale
  • %User Temp%\inH{Random Number}\locale\DLM\NO.locale
  • %User Temp%\inH{Random Number}\locale\DLM\PL.locale
  • %User Temp%\inH{Random Number}\locale\DLM\PT.locale
  • %User Temp%\inH{Random Number}\locale\DLM\RU.locale
  • %User Temp%\inH{Random Number}\locale\DLM\SV.locale
  • %User Temp%\inH{Random Number}\locale\DLM\TR.locale
  • %User Temp%\inH{Random Number}\locale\DLM\ZH.locale
  • %User Temp%\inH{Random Number}\bootstrap_4976.html
  • %User Temp%\in{Random Hex}\{Random Hex}.tmp
  • %User Temp%\{Random Number}.log
  • %User Temp%\{Random Hex}.log

Step 6

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%\inH{Random Number}\css\sdk-ui\images
  • %User Temp%\inH{Random Number}\css\sdk-ui
  • %User Temp%\inH{Random Number}\css
  • %User Temp%\inH{Random Number}\images
  • %User Temp%\inH{Random Number}\locale\DLM
  • %User Temp%\inH{Random Number}\locale
  • %User Temp%\inH{Random Number}
  • %User Temp%\in{Random Hex}

Step 7

Scan your computer with your Trend Micro product to delete files detected as Adware.Win32.Installcore.R002C0RCE25. 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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