PUA_INSTALLCORE.GB

 Analysis by: RonJay Kristoffer Caragay

 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:

530,192 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

15 Jul 2015

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 number}.log
  • %User Temp%\ICReinstall_{grayware filename}.exe
  • %User Temp%\is{random number}\{random number}.cfg
  • %User Temp%\is{random number}\{random number}_Setup.CIS
  • %User Temp%\isf_{random number}.flat
  • %User Temp%\ish{random number}\blank.gif
  • %User Temp%\ish{random number}\bootstrap_{random number}.html
  • %User Temp%\ish{random number}\css\buttons.css
  • %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
  • %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
  • %User Temp%\ish{random number}\css\sdk-ui\images\button-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg.png
  • %User Temp%\ish{random number}\css\sdk-ui\progress-bar.css
  • %User Temp%\ish{random number}\defaultOffer\offer_code.dat
  • %User Temp%\ish{random number}\defaultOffer\offer_html.dat
  • %User Temp%\ish{random number}\images\Bg.gif
  • %User Temp%\ish{random number}\images\close_button.png
  • %User Temp%\ish{random number}\images\finish-button.png
  • %User Temp%\ish{random number}\images\icon.png
  • %User Temp%\ish{random number}\images\loader.gif
  • %User Temp%\ish{random number}\images\next-button.png
  • %User Temp%\ish{random number}\images\next-button-over.png
  • %User Temp%\ish{random number}\images\Progress.png
  • %User Temp%\ish{random number}\images\ProgressBar.png
  • %User Temp%\ish{random number}\images\progress-bg.png
  • %User Temp%\ish{random number}\license.txt
  • %User Temp%\ish{random number}\locale\EN.locale

(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 creates the following folders:

  • %User Temp%\is{random number}
  • %User Temp%\ish{random number}
  • %User Temp%\ish{random number}\css
  • %User Temp%\ish{random number}\defaultOffer
  • %User Temp%\ish{random number}\images
  • %User Temp%\ish{random number}\locale
  • %Program Files%\FLVPlayer

(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.)

Dropping Routine

This potentially unwanted application drops the following files:

  • %Desktop%\Continue FLV Player Installation.lnk
  • %Desktop%\FLV Player.lnk
  • %Program Files%\FLVPlayer\FLVPlayer.exe
  • %Program Files%\FLVPlayer\Uninstall\uninst.dat
  • %Program Files%\FLVPlayer\Uninstall\Uninstall.exe
  • %Start Menu%\FLV Player\FLV Player.lnk
  • %Start Menu%\FLV Player\Uninstall FLV Player.lnk

(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.. %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.. %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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 Details

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

  • http://os.{BLOCKED}yerpro.net/v1.0.1/?v=2.0&c={data}
  • http://cdneu.{BLOCKED}yerpro.net/app/Cmp/FLVPlayer-v2.cis
  • http://cdnus.{BLOCKED}yerpro.net/app/Cmp/FLVPlayer-v2.cis
  • http://cdneu.{BLOCKED}yerpro.net/ofr/BabylonToolbarV7.cis
  • http://cdnus.{BLOCKED}yerpro.net/ofr/BabylonToolbarV7.cis
  • http://rp.{BLOCKED}yerpro.net/?pcrc={data}
  • http://rp.{BLOCKED}yerpro.net/?pcrc={data}

  SOLUTION

Minimum Scan Engine:

9.750

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%\is{random number}
  • %User Temp%\ish{random number}
  • %User Temp%\ish{random number}\css
  • %User Temp%\ish{random number}\defaultOffer
  • %User Temp%\ish{random number}\images
  • %User Temp%\ish{random number}\locale
  • %Program Files%\FLVPlayer

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%\isf_{random number}.flat
  • %Desktop%\Continue FLV Player Installation.lnk
  • %Desktop%\FLV Player.lnk
  • %Start Menu%\FLV Player\FLV Player.lnk
  • %Start Menu%\FLV Player\Uninstall FLV Player.lnk
  • %User Temp%\{random number}.log
  • %User Temp%\ICReinstall_{grayware filename}.exe

Step 5

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


Did this description help? Tell us how we did.