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:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Coinminer

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Spammed via email

This Coinminer arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives as a component bundled with malware/grayware packages.

  TECHNICAL DETAILS

File Size: 1,976,673 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 05 Sep 2018
Payload: Drops files, Connects to URLs/IPs

Arrival Details

This Coinminer arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

Installation

This Coinminer drops and executes the following files:

  • %User Temp%\zip.exe ← Coinminer.MSIL.MALXMR.THAOODAH
  • %User Temp%\leer.vbs ← Worm.VBS.Dunihi.TVP
  • %User Temp%\Tv-Plug-In.exe
  • %User Temp%\__tmp_rar_sfx_access_check_36139816
  • %User Temp%\iisfcgi.dll
  • %User Temp%\iisfreb.dll
  • %User Temp%\iisreqs.dll
  • %User Temp%\iisres.dll
  • %User Temp%\iisRtl.dll
  • %User Temp%\iisutil2.dll
  • %User Temp%\iisvermg.dll
  • %User Temp%\iiswsock.dll
  • %User Temp%\iprestr.dll
  • %User Temp%\browscap.ini
  • %User Temp%\iisexpress.exe
  • %User Temp%\IisExpressAdminCmd.exe
  • %User Temp%\iisexpresstray.exe
  • %User Temp%\authanon.dll
  • %User Temp%\authbas.dll
  • %User Temp%\authcert.dll
  • %User Temp%\authmap.dll
  • %User Temp%\authsspi.dll
  • %User Temp%\browscap.dll
  • %User Temp%\cachtokn.dll
  • %User Temp%\IisExpressadminCmd.resources.dll
  • %User Temp%\iisexpresshelper.dll
  • %User Temp%\iisexpresstray.dll
  • %User Temp%\IisExpressAdminCmd.exe.config
  • %User Temp%\iisexpress.exe.manifest
  • %User Temp%\iisexpressshim.sdb
  • %User Temp%\nsb78C8.tmp\welcome.bmp
  • %User Temp%\nsb78C8.tmp\header.bmp
  • %User Temp%\nsb78C8.tmp\Eula.txt
  • %User Temp%\nsb78C8.tmp\nsDialogs.dll
  • %User Temp%\nsb78C8.tmp\System.dll
  • %User Startup%\leer.vbs ← Worm.VBS.Dunihi.TVP

It adds the following processes:

  • %System%\WScript.exe "%User Temp%\leer.vbs"
  • %User Temp%\zip.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.)

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.542.03
FIRST VSAPI PATTERN DATE: 03 Oct 2018
VSAPI OPR PATTERN File: 14.543.00
VSAPI OPR PATTERN Date: 04 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 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%\__tmp_rar_sfx_access_check_36139816
  • %User Temp%\Tv-Plug-In.exe
  • %User Temp%\zip.exe
  • %User Temp%\leer.vbs
  • %User Temp%\iisfcgi.dll
  • %User Temp%\iisfreb.dll
  • %User Temp%\iisreqs.dll
  • %User Temp%\iisres.dll
  • %User Temp%\iisRtl.dll
  • %User Temp%\iisutil2.dll
  • %User Temp%\iisvermg.dll
  • %User Temp%\iiswsock.dll
  • %User Temp%\iprestr.dll
  • %User Temp%\browscap.ini
  • %User Temp%\iisexpress.exe
  • %User Temp%\IisExpressAdminCmd.exe
  • %User Temp%\iisexpresstray.exe
  • %User Temp%\authanon.dll
  • %User Temp%\authbas.dll
  • %User Temp%\authcert.dll
  • %User Temp%\authmap.dll
  • %User Temp%\authsspi.dll
  • %User Temp%\browscap.dll
  • %User Temp%\cachtokn.dll
  • %User Temp%\IisExpressadminCmd.resources.dll
  • %User Temp%\iisexpresshelper.dll
  • %User Temp%\iisexpresstray.dll
  • %User Temp%\IisExpressAdminCmd.exe.config
  • %User Temp%\iisexpress.exe.manifest
  • %User Temp%\iisexpressshim.sdb
  • %User Temp%\nsb78C8.tmp\welcome.bmp
  • %User Temp%\nsb78C8.tmp\header.bmp
  • %User Temp%\nsb78C8.tmp\Eula.txt
  • %User Temp%\nsb78C8.tmp\nsDialogs.dll
  • %User Temp%\nsb78C8.tmp\System.dll
  • %User Startup%\leer.vbs

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as COINMINER.WIN32.TEVEPLUGS.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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