Analysis by: Elton Rondero
ALIASES:

W32/CoinMiner.BWQ!tr(FORTINET); Trojan.Win32.CoinMiner(IKARUS)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • 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: 144,896 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 22 Apr 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 drops the following files:

  • %Program Files%\Common Files\System\spoolsv.xml
  • %Program Files%\Common Files\System\srv.exe

(Note: %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 adds the following processes:

  • C:\Windows\system32\cmd.exe /c "C:\Program Files\Common Files\System\srv.exe" install

Autostart Technique

This Coinminer registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Logs Service
ImagePath = %Program Files%\Common Files\System\srv.exe

Other Details

This Coinminer connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.159.106
  • {BLOCKED}.{BLOCKED}.159.105
  • {BLOCKED}.{BLOCKED}.159.104
  • {BLOCKED}.{BLOCKED}.159.103

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.960.04
FIRST VSAPI PATTERN DATE: 25 Apr 2019
VSAPI OPR PATTERN File: 14.961.00
VSAPI OPR PATTERN Date: 26 Apr 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

Identify and terminate files detected as Coinminer.Win32.MALXMR.TIAOODCC

[ 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

Delete this registry key

[ 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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Logs Service
    • imagepath = %Program Files%\Common Files\System\srv.exe

Step 5

Search and delete this file

[ 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.  
  • %Program Files%\Common Files\System\spoolsv.xml
  • %Program Files%\Common Files\System\srv.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as Coinminer.Win32.MALXMR.TIAOODCC. 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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