Analysis by: Paul Steven Nadera

ALIASES:

Trojan:Win32/WannaMine.B (Microsoft); MSH.Bluwimps (Norton)

 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 takes advantage of software vulnerabilities to propagate across networks.

It steals certain information from the system and/or the user.

It connects to certain websites to send and receive information. It uses the system's central processing unit (CPU) and/or graphical processing unit (GPU) resources to mine cryptocurrency.

  TECHNICAL DETAILS

File Size: 4,273,376 bytes
File Type: PS1
Memory Resident: Yes
Initial Samples Received Date: 15 Feb 2018
Payload: Connects to URLs/IPs, Steals information, Terminates processes, Downloads 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.

Installation

This Coinminer adds the following processes:

  • netstat -anop -tcp
  • powershell -NoP -NonI -W Hidden `"`$mon = ([WmiClass] 'root\default:Win32_Services').Properties['mon'].Value;`$funs = ([WmiClass] 'root\default:Win32_Services').Properties['funs'].Value ;iex ([System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String(`$funs)));Invoke-Command -ScriptBlock `$RemoteScriptBlock -ArgumentList @(`$mon, `$mon, 'Void', 0, '', '')`"

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • MMLOLSacnner

Other System Modifications

This Coinminer deletes the following files:

  • %Temp%\y1.bat

(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

Propagation

This Coinminer takes advantage of the following software vulnerabilities to propagate across networks:

Process Termination

This Coinminer terminates the following processes if found running in the affected system's memory:

  • powershell -> if it has an established connection to ports 80, 14444, and 14433
  • processes with established connection to ports 3333, 5555, or 7777.

Download Routine

This Coinminer connects to the following website(s) to download and execute a malicious file:

  • If the infected machine is 32-bit, it downloads and executes the following in the accessed C&C:
    • {BLOCKED}.{BLOCKED}.127.157:8000/in3.ps1
    • node.{BLOCKED}v.com/in3.ps1
    • node2.{BLOCKED}v.com/in3.ps1
    • node3.{BLOCKED}v.com/in3.ps1
    • node4.{BLOCKED}v.com/in3.ps1

Information Theft

This Coinminer steals the following information:

  • Domain Credentials via Mimikatz

Other Details

This Coinminer connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.127.157:8000/api.php?data={stolen credentials}
  • node.{BLOCKED}v.com/api.php?data={stolen credentials}
  • node2.{BLOCKED}v.com/api.php?data={stolen credentials}
  • node3.{BLOCKED}v.com/api.php?data={stolen credentials}
  • node4.{BLOCKED}v.com/api.php?data={stolen credentials}

It does the following:

  • It automatically updates itself
  • It deletes the following scheduled task:
    • yastcat
  • It creates the following WMI classes under ROOT\subscription to achieve persistence in the system:
    • CommandLineEventConsumer
      • Name: DSMEventLogConsumer
      • CommandLineTemplate: powershell.exe -NoP -NonI -W Hidden -E {base64 encoded powershell command}
    • __EventFilter
      • Name: DSMEventLogFilter
  • It modifies power configuration settings using the following commands:
    • powercfg /CHANGE -standby-timeout-ac 0 (Standby timeout set to 0 minutes)
    • powercfg /CHANGE -hibernate-timeout-ac 0 (Hibernate timeout set to 0 minutes)
    • powercfg -SetAcValueIndex 381b4222-f694-41f0-9685-ff5bb260df2e 4f971e89-eebd-4455-a8de-9e59040e7347 5ca83367-6e45-459f-a27b-476b1d01c936 000 (Power buttons and lid close action set to do nothing)

It uses the system's central processing unit (CPU) and/or graphical processing unit (GPU) resources to mine cryptocurrency. This behavior makes the system run abnormally slow.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.964.06
FIRST VSAPI PATTERN DATE: 08 Feb 2018
VSAPI OPR PATTERN File: 13.965.00
VSAPI OPR PATTERN Date: 09 Feb 2018

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.PS1.MALXMR.MPL

[ 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

Scan your computer with your Trend Micro product to delete files detected as Coinminer.PS1.MALXMR.MPL. 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:

Step 5

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.


Did this description help? Tell us how we did.