COINMINER_COINHIVE.K-JS

August 24, 2018
 Analysis by: John Anthony Bañes
 ALIASES:

Application.CoinMiner.AY (BitDefender); PUS.JS.Coinhive (Ikarus); Miner.Jswebcoin (Norton)

 PLATFORM:

Windows, Linux, MacOS, Android, iOS

 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:

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 may be hosted on a website and run when a user accesses the said website.

  TECHNICAL DETAILS

File Size:

292 bytes

File Type:

JS, HTML, HTM

Memory Resident:

Yes

Initial Samples Received Date:

17 Aug 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.

It may be hosted on a website and run when a user accesses the said website.

Other Details

This Coinminer does the following:

  • This JavaScript is embedded into websites to run a miner for Monero cryptocurrency.
  • It uses the system's central processing unit (CPU) resources to mine for cryptocurrency.
  • It connects to the following URL to execute the miner:
    • hxxps://{BLOCKED}ve.com/lib/coinhive.min.js

NOTES:

Checks either of the following before it runs its coinminer:

  • WebAssembly
  • asm.js

The script accepts the following relevant parameters:

  • Target number of mining threads per tab
  • Throttle rate
  • Execution / Start - mode
  • Target number of hashes to solve

It can have the following start modes:

  • IF_EXCLUSIVE_TAB - The miner will only start if no other tabs are already mining.
  • FORCE_EXCLUSIVE_TAB - The miner will always start and immediately kill all miners in other tabs that have not specified CoinHive.FORCE_MULTI_TAB.
  • FORCE_MULTI_TAB - The miner will always start.

It has the capability to monitor the following events:

  • open
  • authed
  • close
  • error
  • job
  • found
  • accepted
  • optin

It sends events and other data to the following URLs/Websocket Shards:

  • wss://ws001.{BLOCKED}ve.com/proxy
  • wss://ws002.{BLOCKED}ve.com/proxy
  • wss://ws003.{BLOCKED}ve.com/proxy
  • wss://ws004.{BLOCKED}ve.com/proxy
  • wss://ws005.{BLOCKED}ve.com/proxy
  • wss://ws006.{BLOCKED}ve.com/proxy
  • wss://ws007.{BLOCKED}ve.com/proxy
  • wss://ws008.{BLOCKED}ve.com/proxy
  • wss://ws009.{BLOCKED}ve.com/proxy
  • wss://ws010.{BLOCKED}ve.com/proxy
  • wss://ws011.{BLOCKED}ve.com/proxy
  • wss://ws012.{BLOCKED}ve.com/proxy
  • wss://ws013.{BLOCKED}ve.com/proxy
  • wss://ws014.{BLOCKED}ve.com/proxy
  • wss://ws015.{BLOCKED}ve.com/proxy
  • wss://ws016.{BLOCKED}ve.com/proxy
  • wss://ws017.{BLOCKED}ve.com/proxy
  • wss://ws018.{BLOCKED}ve.com/proxy
  • wss://ws019.{BLOCKED}ve.com/proxy
  • wss://ws020.{BLOCKED}ve.com/proxy
  • wss://ws021.{BLOCKED}ve.com/proxy
  • wss://ws022.{BLOCKED}ve.com/proxy
  • wss://ws023.{BLOCKED}ve.com/proxy
  • wss://ws024.{BLOCKED}ve.com/proxy
  • wss://ws024.{BLOCKED}ve.com/proxy
  • wss://ws025.{BLOCKED}ve.com/proxy
  • wss://ws026.{BLOCKED}ve.com/proxy
  • wss://ws027.{BLOCKED}ve.com/proxy
  • wss://ws028.{BLOCKED}ve.com/proxy
  • wss://ws029.{BLOCKED}ve.com/proxy
  • wss://ws030.{BLOCKED}ve.com/proxy
  • wss://ws031.{BLOCKED}ve.com/proxy
  • wss://ws032.{BLOCKED}ve.com/proxy

It accesses the following libraries:

  • https://{BLOCKED}ve.com/lib/worker-asmjs.min.js?v7
  • https://{BLOCKED}ve.com/captcha
  • https://{BLOCKED}ve.com/media/miner.html
  • https://{BLOCKED}mine.com/authenticate.html

It connects and executes https://js.{BLOCKED}s.51.la/19575631.js for reporting and sends the following information:

  • Screen resolution
  • If accessed on mobile
  • URL where the script is embedded

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.458.02

FIRST VSAPI PATTERN DATE:

22 Aug 2018

VSAPI OPR PATTERN File:

14.459.00

VSAPI OPR PATTERN Date:

23 Aug 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

Close all opened browser windows

Step 3

Scan your computer with your Trend Micro product to delete files detected as COINMINER_COINHIVE.K-JS. 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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