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Coinminer.MSIL.MALXMR.TIAOODBL

September 10, 2021
 Analysis by: Arianne Grace Dela Cruz
 ALIASES:

Trojan:MSIL/AgentTesla.CHH!MTB (MICROSOFT); Trojan.MSIL.Krypt (IKARUS)

 PLATFORM:

Windows

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

  • Threat Type: Coinminer

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, 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 may be dropped by other malware.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

945,152 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

30 Aug 2021

Payload:

Drops files

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 may be dropped by the following malware:

Installation

This Coinminer drops and executes the following files:

  • %User Temp%\{chrome2 or setup}.exe - drops and executes the following:
    • %Application Data%\services64.exe - miner downloader module
    • %Application Data%\Libs\sihost64.exe - watchdog
    • %Application Data%\Libs\WR64.sys

(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
srevices64 = %Application Data%\services64.exe - Only added if not ran as administrator

Other System Modifications

This Coinminer deletes the following files:

  • %Application Data%\Libs\sihost64.log
  • %Application Data%\Libs\sihost64-2.log

(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).)

Download Routine

This Coinminer connects to the following URL(s) to download its component file(s):

  • https://{BLOCKED}m.net:58899/assets/txt/resource_url.php?type=xmrig
  • https://{BLOCKED}b.com/UnamSanctam/SilentXMRMiner/raw/master/SilentXMRMiner/Resources/xmrig.zip

As of this writing, the said sites are inaccessible.

Information Theft

This Coinminer gathers the following data:

  • Computer Name

Other Details

This Coinminer does the following:

  • It will not proceed with its intended routine if any of the following conditions are met:
    • Presence of the following strings in the machine's manufacturer model:
      • Virtual
      • vmware
      • VirtualBox
    • Running under a debugger or emulator
  • It uses the following commandline for the miner module once downloaded successfully:
    • --cinit-find-x -B --algo=rx/0 --asm=auto --cpu-memory-pool=1 --randomx-mode=auto --randomx-no-rdmsr --cuda-bfactor-hint=12 --cuda-bsleep-hint=100 --url=xmr-eu2.nanopool.org:14433 --user={BLOCKED}kV653RD7zSYeXSWRu1wnEDzPgFDFwntSnuRx7g4HbHPqNDGS6BW1bget6yyHyrPbBcVsdR6Ebxd843bMuK.main/password {BLOCKED}hint=30 --cinit-remote-config=\"v4Qq47ngFyBcSyO2uLKc6BJ+edII5Fll530cZ/+msGEWovb73nU3RrOnuNmRoFcg\" --cinit-idle-wait=5 --cinit-idle-cpu=70 --tls --cinit-stealth

It checks if the following virtual machine or sandbox related module(s) is loaded in the affected system:

  • SbieDll.dll - terminates itself when found

It adds the following scheduled tasks:

  • Added only if run as administrator:
    • Task Name: services64
    • Task to be ran: %Application Data%\services64.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).)

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

16.950.04

FIRST VSAPI PATTERN DATE:

06 Sep 2021

VSAPI OPR PATTERN File:

16.951.00

VSAPI OPR PATTERN Date:

07 Sep 2021

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     TROJ.Win32.TRX.XXPE50FFF047

Step 2

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 3

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 4

Restart in Safe Mode

[ Learn More ]

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
    • srevices64 = %Application Data%\services64.exe

Step 6

Deleting Scheduled Tasks

The following {Task Name} - {Task to be run} listed should be used in the steps identified below:

  • Task Name: services64
  • Task to be run: %Application Data%\services64.exe

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
    System Tools>Scheduled Tasks.
  2. Locate each {Task Name} values listed above in the Name column.
  3. Right-click on the said file(s) with the aforementioned value.
  4. Click on Properties. In the Run field, check for the listed {Task to be run}.
  5. If the strings match the list above, delete the task.

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

  1. Open the Windows Task Scheduler. To do this:
    • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
    • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
  2. In the left panel, click Task Scheduler Library.
  3. In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
  4. In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
  5. If the said string is found, delete the task.

Step 7

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%\{chrome2 or setup}.exe
  • %Application Data%\services64.exe
  • %Application Data%\Libs\sihost64.exe
  • %Application Data%\Libs\WR64.sys

Step 8

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