TROJ_COINMINER.AUSW

 Analysis by: Joselyn Canuela

 ALIASES:

CoinMiner.JNS (AVG), MemScan:Trojan.BitCoinMiner.BH (BitDefender), Trojan.Miner.Adylkuzz (Ikarus), Trojan:Win32/CoinMiner.AZ!bit (Microsoft)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

This Trojan 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:

1,443,844 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

12 May 2017

Payload:

Connects to URLs/IPs

Arrival Details

This Trojan 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 Trojan adds the following processes:

  • cmd.exe /c taskkill /f /im hdmanager.exe
  • C:\Windows\Fonts\LMS.exe -a cryptonight -o stratum+tcp://xmr.{BLOCKED}-pool.fr:443 -p x -u 41rFhY1SKNXNyr3dMqsWqkNnkny8pVSvhiDuTA3zCp1aBqJfFWSqR7Wj2hoMzEMUR1JGjhvbXQnnQ3zmbvvoKVuZV2avhJh -t 1

Autostart Technique

This Trojan adds and runs the following services:

  • Display Name: Microsoft .NET Framework NGEN v4.0.30339
  • Binary Path Name: C:\WINDOWS\Fonts\sppsrv.exe
  • Service Name: clr_optimization_v4.0.30339

Download Routine

This Trojan connects to the following URL(s) to download its configuration file:

  • https://g.{BLOCKED}oweb.com/64.exe -> (downloaded if malware is executed in 64-bit OS) detected as HKTL64_COINMINE.JC
  • https://g.{BLOCKED}oweb.com/miner2.txt -> contains configuration of the miner
  • https://g.{BLOCKED}oweb.com/86.exe -> saves as C:\Windows\Fonts\LMS.exe - detected as HKTL_COINMINE.JC

NOTES:

It renames itself to the following:

  • C:\Windows\Fonts\sppsrv.exe
  • This malware uses the system’s CPU to mine bitcoins.

    It connects to the following mining pool(s):

  • stratum+tcp//xmr.{BLOCKED}-pool.fr:443

  •   SOLUTION

    Minimum Scan Engine:

    9.850

    FIRST VSAPI PATTERN FILE:

    13.404.04

    FIRST VSAPI PATTERN DATE:

    13 May 2017

    VSAPI OPR PATTERN File:

    13.405.00

    VSAPI OPR PATTERN Date:

    14 May 2017

    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, and then delete this registry key

    [ 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.

    • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\clr_optimization_v4.0.30339

    Step 4

    Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_COINMINER.AUSW. 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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