PUA_INSTACORE

 Analysis by: RonJay Kristoffer Caragay

 ALIASES:

PUP.Optional.InstallCore.SID.A (Malwarebytes); Riskware/InstallCore (Fortinet); InstallCore (fs) (Sunbelt); a variant of Win32/InstallCore.YV potentially unwanted (ESET-NOD32); Install Core Click run software (Sophos)

 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:

{varies} bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

29 Jun 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_{number}.exe
  • %User Temp%\is{random number}\{random number}_stp.EXE
  • %User Temp%\is{random number}\{random number}_stp.EXE.part
  • %User Temp%\ish{random number}\bootstrap_{number}.html
  • %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.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg2.png
  • %User Temp%\ish{random number}\css\sdk-ui\images\progress-bg-corner.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\default_tb.png
  • %User Temp%\ish{random number}\images\default_wi.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\Icon_Generic.png
  • %User Temp%\ish{random number}\images\Loader.gif
  • %User Temp%\ish{random number}\images\Pause_Button.png
  • %User Temp%\ish{random number}\images\Progress.png
  • %User Temp%\ish{random number}\images\ProgressBar.png
  • %User Temp%\ish{random number}\images\Quick_Specs.png
  • %User Temp%\ish{random number}\images\Resume_Button.png
  • %User Temp%\ish{random number}\images\sponsored.png
  • %User Temp%\ish{random number}\images\text-bg.png
  • %User Temp%\ish{random number}\locale\CS.locale
  • %User Temp%\ish{random number}\locale\DA.locale
  • %User Temp%\ish{random number}\locale\DE.locale
  • %User Temp%\ish{random number}\locale\EL.locale
  • %User Temp%\ish{random number}\locale\EN.locale
  • %User Temp%\ish{random number}\locale\ES.locale
  • %User Temp%\ish{random number}\locale\FI.locale
  • %User Temp%\ish{random number}\locale\FR.locale
  • %User Temp%\ish{random number}\locale\ID.locale
  • %User Temp%\ish{random number}\locale\IT.locale
  • %User Temp%\ish{random number}\locale\JA.locale
  • %User Temp%\ish{random number}\locale\KO.locale
  • %User Temp%\ish{random number}\locale\NL.locale
  • %User Temp%\ish{random number}\locale\NO.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\SV.locale
  • %User Temp%\ish{random number}\locale\TR.locale
  • %User Temp%\ish{random number}\locale\ZH.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}\images
  • %User Temp%\ish{random number}\locale
  • %User Temp%\ish{random number}\dat

(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 Details

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

  • http://giserv.{BLOCKED}no.com/details
  • http://info.{BLOCKED}no.com/?v=1.03&c={data}
  • http://os.{BLOCKED}no.com/Coinis/?v=5.0&c={data}
  • http://os2.{BLOCKED}no.com/Coinis/?v=5.0&c={data}
  • http://rp.{BLOCKED}no.com/?pcrc={data}
  • http://emb.{BLOCKED}twareking.com/cast/emb.html
  • http://os.{BLOCKED}twareking.com/MEDIA_YTZ/?v=5.0&c={data}
  • http://os2.{BLOCKED}twareking.com/Aff-AD/?v=5.0&c={data}
  • http://rp.{BLOCKED}twareking.com/?pcrc={data}
  • http://info.{BLOCKED}v.com/?v=1.03&c=?pcrc={data}
  • http://os.{BLOCKED}v.com/Vittalia/?v=5.0&c={data}
  • http://rp.{BLOCKED}v.com/?pcrc={data}
  • http://cdneu.{BLOCKED}iacdn.com/ofr/Malaromoro/Malaromoro.cis
  • http://cdneu.{BLOCKED}iacdn.com/ofr/Mapayuy/Mapayuy_0819.cis
  • http://cdnus.{BLOCKED}iacdn.com/ofr/Malaromoro/Malaromoro.cis
  • http://cdnus.{BLOCKED}iacdn.com/ofr/Mapayuy/Mapayuy_0819.cis

  SOLUTION

Minimum Scan Engine:

9.750

SSAPI PATTERN File:

1.607.00

SSAPI PATTERN Date:

18 Mar 2015

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}\images
  • %User Temp%\ish{random number}\locale
  • %User Temp%\ish{random number}\dat

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%\{random number}.log
  • %User Temp%\ICReinstall_{number}.exe

Step 5

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