Coinminer_MALXMR.SMSTAK1-WIN64

October 22, 2019
 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Coinminer

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Coinminer 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:

5,788,710 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

22 Oct 2019

Arrival Details

This Coinminer 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 Coinminer adds the following processes:

  • "%System%\WScript.exe" "%User Temp%\RarSFX0\Cr_Blocker_v11.vbs"
  • %User Temp%\RarSFX0\Cr_Blocker_v11.vbs
  • "%User Temp%\RarSFX0\Win_cr_blocker.exe"
  • Win_cr_blocker.exe
  • "%Program Files%\Internet Explorer\IEXPLORE.EXE" SCODEF:2148 CREDAT:275457 /prefetch:2

(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).. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • %Application Data%\Microsoft\Windows\DNTException
  • %AppDataLocal%\Microsoft\Internet Explorer\DomainSuggestions
  • %User Temp%\RarSFX0
  • %Application Data%\Microsoft\Windows\IECompatCache
  • %Application Data%\Microsoft\Windows\PrivacIE
  • %User Profile%\AppData
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active
  • %System Root%\Users
  • %Application Data%\Microsoft\Windows\IECompatUACache

(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).. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %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).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Autostart Technique

This Coinminer drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\Autorun_blocker.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

Other System Modifications

This Coinminer deletes the following files:

  • %AppDataLocal%Low\Microsoft\Internet Explorer\Services\search_{0633EE93-D776-472f-A0FF-E1416B8B2E3A}.ico

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

Dropping Routine

This Coinminer drops the following files:

  • %User Temp%\RarSFX0\Cr_Blocker_v11.vbs
  • %User Temp%\RarSFX0\config.txt
  • %User Temp%\RarSFX0\libeay32.dll
  • %User Temp%\RarSFX0\xmrstak_cuda_backend.dll
  • %AppDataLocal%\Microsoft\Internet Explorer\MSIMGSIZ.DAT
  • %User Temp%\RarSFX0\xmrstak_opencl_backend.dll
  • %AppDataLocal%\Microsoft\Internet Explorer\DomainSuggestions\en-US.6
  • %User Temp%\RarSFX0\pools.txt
  • %User Temp%\RarSFX0\cpu.txt
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\{BF78C719-9667-11E9-B41C-005056BC5B9B}.dat
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\RecoveryStore.{BF78C717-9667-11E9-B41C-005056BC5B9B}.dat
  • %User Temp%\RarSFX0\ssleay32.dll
  • %User Temp%\RarSFX0\Win_cr_blocker.exe
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\{C996AFF2-9667-11E9-B41C-005056BC5B9B}.dat

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

Other Details

This Coinminer connects to the following possibly malicious URL:

  • http://go.{BLOCKED}oft.com
  • http://www.{BLOCKED}ingpro.com
  • http://api.{BLOCKED}g.com
  • http://www.{BLOCKED}g.com
  • http://ieonline.{BLOCKED}oft.com
  • http://sqm.{BLOCKED}try.microsoft.com

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.850

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

Restart in Safe Mode

[ Learn More ]

Step 3

Identify and terminate files detected as Coinminer_MALXMR.SMSTAK1-WIN64

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Search and delete these components

[ Learn More ]
There may be some components 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%\RarSFX0\Cr_Blocker_v11.vbs
  • %User Temp%\RarSFX0\config.txt
  • %User Temp%\RarSFX0\libeay32.dll
  • %User Temp%\RarSFX0\xmrstak_cuda_backend.dll
  • %AppDataLocal%\Microsoft\Internet Explorer\MSIMGSIZ.DAT
  • %User Temp%\RarSFX0\xmrstak_opencl_backend.dll
  • %AppDataLocal%\Microsoft\Internet Explorer\DomainSuggestions\en-US.6
  • %User Temp%\RarSFX0\pools.txt
  • %User Temp%\RarSFX0\cpu.txt
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\{BF78C719-9667-11E9-B41C-005056BC5B9B}.dat
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\RecoveryStore.{BF78C717-9667-11E9-B41C-005056BC5B9B}.dat
  • %User Temp%\RarSFX0\ssleay32.dll
  • %User Temp%\RarSFX0\Win_cr_blocker.exe
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active\{C996AFF2-9667-11E9-B41C-005056BC5B9B}.dat

Step 5

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.
  • %Application Data%\Microsoft\Windows\DNTException
  • %AppDataLocal%\Microsoft\Internet Explorer\DomainSuggestions
  • %User Temp%\RarSFX0
  • %Application Data%\Microsoft\Windows\IECompatCache
  • %Application Data%\Microsoft\Windows\PrivacIE
  • %User Profile%\AppData
  • %AppDataLocal%\Microsoft\Internet Explorer\Recovery\High\Active
  • %System Root%\Users
  • %Application Data%\Microsoft\Windows\IECompatUACache

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Coinminer_MALXMR.SMSTAK1-WIN64. 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.

Step 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %AppDataLocal%Low\Microsoft\Internet Explorer\Services\search_{0633EE93-D776-472f-A0FF-E1416B8B2E3A}.ico


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