Modified by: Arvin Roi Macaraeg

ALIASES:

AdWare.Win32.Vosteran.heur(KASPERSKY);

 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

Infection Channel: 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 connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 811,056 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 May 2019
Payload: Connects to URLs/IPs, Displays windows

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%\ish{random number}\css\ie6_main.css
  • %User Temp%\ish{random number}\css\main.css
  • %User Temp%\ish{random number}\css\sdk-ui\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-corner.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random number}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random number}\csshover3.htc
  • %User Temp%\ish{random number}\dat\upd.DAT
  • %User Temp%\ish{random number}\form.bmp.Mask
  • %User Temp%\ish{random number}\images\bg.png
  • %User Temp%\ish{random number}\images\Close.png
  • %User Temp%\ish{random number}\images\Close_Hover.png
  • %User Temp%\ish{random number}\images\Color_Button.png
  • %User Temp%\ish{random number}\images\Color_Button_Hover.png
  • %User Temp%\ish{random number}\images\Grey_Button.png
  • %User Temp%\ish{random number}\images\Grey_Button_Hover.png
  • %User Temp%\ish{random number}\images\Loader.gif
  • %User Temp%\ish{random number}\images\Progress.png
  • %User Temp%\ish{random number}\images\ProgressBar.png
  • %User Temp%\ish{random number}\images\text-bg.png
  • %User Temp%\ish{random number}\locale\DE.locale
  • %User Temp%\ish{random number}\locale\EN.locale
  • %User Temp%\ish{random number}\locale\ES.locale
  • %User Temp%\ish{random number}\locale\FR.locale
  • %User Temp%\ish{random number}\locale\IT.locale
  • %User Temp%\ish{random number}\locale\PL.locale
  • %User Temp%\ish{random number}\locale\PT.locale
  • %User Temp%\ish{random number}\locale\RU.locale
  • %User Temp%\ish{random number}\locale\UA.locale
  • %User Temp%\ish{random number}\bootstrap_58853.html
  • %Common Programs%\FlvPlayer\FlvPlayer.lnk
  • %Common Programs%\FlvPlayer\Uninstall.lnk

(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).. %Common Programs% is the folder that contains common program groups for all users, which is usually C:\Documents and Settings\All Users\Start Menu\Programs on Windows 2000, XP, and Server 2003, or C:\ProgramData\Microsoft\Windows\Start Menu\Programs on Windows Vista, 7, and 8.)

Other Details

This Potentially Unwanted Application adds the following lines or registry entries as part of its routine:

    • HKEY_LOCAL_MACHINE\SOFTWARE\FlvPlayer
      Path = "%Application Data%\FlvPlayer"
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      DisplayName = "FlvPlayer"
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      DisplayVersion = "${VERSION}"
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      Publisher = ""
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      URLInfoAbout = "${URL}"
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      DisplayIcon = "%Application Data%\FlvPlayer\uninstall.exe"
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      UninstallString = "%Application Data%\FlvPlayer\uninstall.exe"
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      NoModify = 1
    • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
      NoRepair = 1

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It connects to the following website to send and receive information:

  • http://rp.{BLOCKED}tinstall.com/?pcrc={CRC value}&v={version}
  • http://os.{BLOCKED}tinstall.com/MEDIA_YTZ/?v={version}&c=1619676736
  • http://os2.{BLOCKED}tinstall.com/Aff-AD/?v={Version}&c=1619676736
  • http://emb.{BLOCKED}tinstall.com/sk-logabpstatus.php?a={information for logs}=false

It does the following:

  • It displays the following during installation:

  SOLUTION

Minimum Scan Engine: 9.850
SSAPI PATTERN File: 2.175.00
SSAPI PATTERN Date: 16 May 2019

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\FlvPlayer
    • Path = "%Application Data%\FlvPlayer"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • DisplayName = "FlvPlayer"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • DisplayVersion = "${VERSION}""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • Publisher = ""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • URLInfoAbout = "${URL}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • DisplayIcon = "%Application Data%\FlvPlayer\uninstall.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • UninstallString = "%Application Data%\FlvPlayer\uninstall.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • NoModify = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\FlvPlayer
    • NoRepair = "1"

Step 4

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%\ish{random number}\css\ie6_main.css
  • %User Temp%\ish{random number}\css\main.css
  • %User Temp%\ish{random number}\css\sdk-ui\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-corner.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random number}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random number}\csshover3.htc
  • %User Temp%\ish{random number}\dat\upd.DAT
  • %User Temp%\ish{random number}\form.bmp.Mask
  • %User Temp%\ish{random number}\images\bg.png
  • %User Temp%\ish{random number}\images\Close.png
  • %User Temp%\ish{random number}\images\Close_Hover.png
  • %User Temp%\ish{random number}\images\Color_Button.png
  • %User Temp%\ish{random number}\images\Color_Button_Hover.png
  • %User Temp%\ish{random number}\images\Grey_Button.png
  • %User Temp%\ish{random number}\images\Grey_Button_Hover.png
  • %User Temp%\ish{random number}\images\Loader.gif
  • %User Temp%\ish{random number}\images\Progress.png
  • %User Temp%\ish{random number}\images\ProgressBar.png
  • %User Temp%\ish{random number}\images\text-bg.png
  • %User Temp%\ish{random number}\locale\DE.locale
  • %User Temp%\ish{random number}\locale\EN.locale
  • %User Temp%\ish{random number}\locale\ES.locale
  • %User Temp%\ish{random number}\locale\FR.locale
  • %User Temp%\ish{random number}\locale\IT.locale
  • %User Temp%\ish{random number}\locale\PL.locale
  • %User Temp%\ish{random number}\locale\PT.locale
  • %User Temp%\ish{random number}\locale\RU.locale
  • %User Temp%\ish{random number}\locale\UA.locale
  • %User Temp%\ish{random number}\bootstrap_58853.html
  • %Common Programs%\FlvPlayer\FlvPlayer.lnk
  • %Common Programs%\FlvPlayer\Uninstall.lnk

Step 5

Remove PUA.Win32.InstallCore.WFEJMO by using its own Uninstall option

[ Learn More ]
To uninstall the grayware process

Step 6

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.InstallCore.WFEJMO. 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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