COINMINER.MSIL.MALXMR.TIAOODAI

November 10, 2018
 Analysis by: John Donnie Celestre
 ALIASES:

HEUR:Trojan.MSIL.Miner.gen (KASPERSKY); Trojan:MSIL/CoinMiner (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Coinminer

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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.

  TECHNICAL DETAILS

File Size:

52,736 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 Nov 2018

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 copies of itself into the affected system and executes them:

  • %Windows%\Help\csrss.exe
  • %Windows%\system\csrss.exe

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

It adds the following processes:

  • "C:\Windows\System32\attrib.exe" C:\Windows\Help\csrss.exe -s -r -a -h
  • "C:\Windows\System32\attrib.exe" C:\Windows\Help\lsass.exe -s -r -a -h
  • "C:\Windows\System32\attrib.exe" C:\Windows\system\csrss.exe -s -r -a -h
  • "C:\Windows\System32\cacls.exe" C:\Windows\Help\csrss.exe /e /g system:f
  • "C:\Windows\System32\cacls.exe" C:\Windows\Help\lsass.exe /e /g everyone:f
  • "C:\Windows\System32\cacls.exe" C:\Windows\Help\lsass.exe /e /g system:f
  • "C:\Windows\System32\cacls.exe" C:\Windows\Help\csrss.exe /e /g everyone:f
  • "C:\Windows\System32\cacls.exe" C:\Windows\system\csrss.exe /e /g everyone:f
  • "C:\Windows\System32\cacls.exe" C:\Windows\system\csrss.exe /e /g system:f

Autostart Technique

This Coinminer starts the following services:

    • Service Name: wmiApSrvs
    • Display Name: WMI Performance Adaptor
    • Start Type: SERVICE_AUTO_START
    • Binary Pathname: %Windows%\Help\csrss.exe -s
    • Service Name: wmiApSrvs
    • Display Name: WMI Performance Adaptor
    • Start Type: SERVICE_AUTO_START
    • Binary Pathname: %Windows%\Help\csrss.exe -p

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

Other System Modifications

This Coinminer deletes the following files:

  • %Windows%\Help\n.exe
  • %Windows%\Help\c.exe
  • %Windows%\Help\csrss.exe
  • %Windows%\Help\lsass.exe
  • %Windows%\system\csrss.exe

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

Other Details

This Coinminer connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.80.200:8080/

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.610.03

FIRST VSAPI PATTERN DATE:

06 Nov 2018

VSAPI OPR PATTERN File:

14.611.00

VSAPI OPR PATTERN Date:

07 Nov 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

Disable this malware service

[ Learn More ]
  • wmiApSrvs

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.  
  • %Windows%\Help\csrss.exe
  • %Windows%\system\csrss.exe

Step 6

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