Coinminer.MSIL.MALXMR.SMH

February 28, 2020
 ALIASES:

TrojanDownloader:MSIL/Pstinb.M (Microsoft); GenericRXIQ-ZY!B2BE5D138AF8 (McAfee); HEUR:Trojan.MSIL.Generic (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)

 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:

167,936 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 Feb 2020

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 creates the following folders:

  • %Application Data%\svchost\m
  • %Application Data%\svchost

(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).)

Autostart Technique

This Coinminer adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Host Process for Windows Services = "%Application Data%\svchost\svchost.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
0 = "{random characters}"

Other System Modifications

This Coinminer deletes the following files:

  • %User Temp%\C

(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 modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "%Application Data%\svchost\svchost.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "{random characters}"

Dropping Routine

This Coinminer drops the following files:

  • %Application Data%\svchost\m\cpuminer-conf.json
  • %Application Data%\svchost\svchost.exe

(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).)

Other Details

This Coinminer connects to the following possibly malicious URL:

  • http://{BLOCKED}.236.29/putstorage/DownloadFile.ashx?{random characters}
  • http://d.{BLOCKED}e.ro
  • http://www.{BLOCKED}x.com
  • {BLOCKED}.63.68
  • {BLOCKED}9.1

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

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Host Process for Windows Services = "%Application Data%\svchost\svchost.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • 0 = "{random characters}"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • Load = "%Application Data%\svchost\svchost.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • Load = "{random characters}"

Step 5

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.
  • %Application Data%\svchost\m\cpuminer-conf.json
  • %Application Data%\svchost\svchost.exe

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.
  • %Application Data%\svchost\m
  • %Application Data%\svchost

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Coinminer.MSIL.MALXMR.SMH. 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 8

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.

  • %User Temp%\C


Did this description help? Tell us how we did.