COINMINER_MALXMR.AB-WIN64

 Analysis by: Rheniel Rhay Ramos

 ALIASES:

Trojan.Win64.Miner.bem (Kaspersky); Trojan:Win32/Coinminer!bit (Microsoft); Trojan.Coinminer (Symantec)

 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, Downloaded from the Internet

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 creates folders where it drops its files.

It uses the system's central processing unit (CPU) and/or graphical processing unit (GPU) resources to mine cryptocurrency.

  TECHNICAL DETAILS

File Size:

377,344 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

26 Feb 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.

Installation

This Coinminer drops the following files:

  • %User Temp%\IXP000.TMP\TMP{random}.TMP -> deleted afterwards
  • %User Temp%\IXP000.TMP\audiodig.exe
  • %User Temp%\IXP000.TMP\audiodig
  • %User Temp%\IXP000.TMP\audiodig.reg
  • %System Root%\SysWOW64\audiodig -> Miner config file
  • %System Root%\SysWOW64\init.bat

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It drops and executes the following files:

  • %User Temp%\IXP000.TMP\init.bat -> used to copy the files from Temp to %System Root%\SysWow64\
  • %System Root%\SysWOW64\audiodig.exe -> Miner
  • %System Root%\SysWOW64\audiodig.reg -> used to add autostart registry

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
XMRRUN = "%System Root%\Windows\SysWOW64\audiodig.exe -c %System Root%\Windows\SysWOW64\audiodig"

Other System Modifications

This Coinminer adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
wextract_cleanup0 = "rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 "%User Temp%\IXP000.TMP\""

Other Details

This Coinminer does the following:

  • It deletes the following folder and all of its contents if it fails to copy them in the %System Root%\SysWOW64\ directory:
    • %User Temp%\IXP000.TMP\
  • It uses the following details for its mining capabilities:
    • url: pool.{BLOCKED}s.in:8080
    • user: NewWorld
    • pass: 1

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:

14.138.04

FIRST VSAPI PATTERN DATE:

19 Mar 2018

VSAPI OPR PATTERN File:

14.139.00

VSAPI OPR PATTERN Date:

20 Mar 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

Identify and terminate files detected as COINMINER_MALXMR.AB-WIN64

[ 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 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • XMRRUN = "%System Root%\Windows\SysWOW64\audiodig.exe -c %System Root%\Windows\SysWOW64\audiodig"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • wextract_cleanup0 = "rundll32.exe %System%\advpack.dll,DelNodeRunDLL32 "%User Temp%\IXP000.TMP\""

Step 5

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%\IXP000.TMP\TMP{random}.TMP
  • %User Temp%\IXP000.TMP\audiodig
  • %User Temp%\IXP000.TMP\audiodig.exe
  • %User Temp%\IXP000.TMP\audiodig.reg
  • %User Temp%\IXP000.TMP\init.bat
  • %System Root%\SysWOW64\audiodig
  • %System Root%\SysWOW64\audiodig.exe
  • %System Root%\SysWOW64\audiodig.reg
  • %System Root%\SysWOW64\init.bat

Step 6

Scan your computer with your Trend Micro product to delete files detected as COINMINER_MALXMR.AB-WIN64. 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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