Coinminer.MSIL.MALXMR.THAOODAH

 Analysis by: Robert Nicole Malagad

 ALIASES:

HEUR:Trojan.MSIL.Miner.gen (Kaspersky), MSIL/CoinMiner.AQZ!tr (Fortinet)

 PLATFORM:

Windows

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

  • Threat Type: Coinminer

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware


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. It arrives as a component bundled with malware/grayware packages.

  TECHNICAL DETAILS

File Size:

771,584 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Sep 2018

Payload:

Connects to URLs/IPs

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.

It arrives as a component bundled with malware/grayware packages.

Installation

This Coinminer drops the following files:

  • %AppDataLocal%\{Random Characters}\SystemProcess.exe
  • %User Temp%\{Random Characters}\{Random Characters}.exe ← Coinminer.Win32.MALXMR.TIBAGB
  • %System%\Tasks\{Random Characters}

It adds the following processes:

  • schtasks.exe /create /tn {Random Characters} /tr %AppDataLocal%\{Random Characters}\SystemProcess.exe /sc minute /mo 1
  • %AppDataLocal%\Temp\{Random Characters}\{Random Characters}.exe -o xmr.pool.{BLOCKED}ate.com:45700 -u datildequeso@{BLOCKED}l.com -p x -a cryptonight -t 3 -x %proxy%

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
{Random Characters} = %AppDataLocal%\{Random Characters}\SystemProcess.exe

Other Details

This Coinminer does the following:

  • It uses the following details as part of its coinminer routine:
    • o:xmr.pool.{BLOCKED}ate.com:45700
    • username:datildequeso@{BLOCKED}l.com
    • password:x
    • a:cryptonight
    • t:3
    • x:%proxy%

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.544.04

FIRST VSAPI PATTERN DATE:

04 Oct 2018

VSAPI OPR PATTERN File:

14.545.00

VSAPI OPR PATTERN Date:

05 Oct 2018

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

Restart in Safe Mode

[ Learn More ]

Step 4

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.  
  • %AppDataLocal%\{Random Characters}\SystemProcess.exe
  • %User Temp%\{Random Characters}\{Random Characters}.exe
  • %System%\Tasks\{Random Characters}

Step 5

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
    • {Random Characters} = %AppDataLocal%\{Random Characters}\SystemProcess.exe

Step 6

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