Analysis by: Michael Jhon Ofiaza
 PLATFORM:

Linux

 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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 2,750 bytes
File Type: Other
Memory Resident: No
Initial Samples Received Date: 09 Oct 2018
Payload: Connects to URLs/IPs, Terminates processes

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 adds the following processes:

  • xm.service

Process Termination

This Coinminer terminates the following processes if found running in the affected system's memory:

  • xmrig
  • proc
  • xmr-stak
  • minergate-cli
  • bashd.service -> also disabled from starting automatically

Download Routine

This Coinminer accesses the following websites to download files:

  • http://{BLOCKED}.{BLOCKED}.105.187/k.php
  • http://{BLOCKED}.{BLOCKED}.105.187/data.cfg
  • http://{BLOCKED}.{BLOCKED}.105.187/xm
  • http://{BLOCKED}.{BLOCKED}.105.187/xm.service
  • http://{BLOCKED}.{BLOCKED}.105.187/test.sh
  • http://{BLOCKED}.{BLOCKED}.105.187/test3.sh

It saves the files it downloads using the following names:

  • {Malware Path}/data.cfg
  • {Malware Path}/xm
  • {Malware Path}/test.sh
  • {Malware Path}/test3.sh
  • /etc/systemd/system/xm.service

Other Details

This Coinminer does the following:

  • Creates users "richard" and "frank" then grant them root privileges
  • Reconfigure the secure socket shell (SSH) daemon to allow password authentication, and restart the SSH daemon
  • Make the downloaded scripts executable
  • Scan all networks seen from the host w/ scan rate of 50,000 packets per second for open ports 2375 and 2376 and save the result into local.txt file
  • Spread laterally by automatically replicating the tools to the hosts found in previous reconnaissance scans
  • Check the persistence of the Monero-mining process and start the process, it if it is not running
  • Install the following packages:
    • systemd
    • masscan
    • iproute2

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.566.05
FIRST VSAPI PATTERN DATE: 15 Oct 2018
VSAPI OPR PATTERN File: 14.567.00
VSAPI OPR PATTERN Date: 16 Oct 2018

Scan your computer with your Trend Micro product to delete files detected as Coinminer.SH.MALXMR.ATNH. 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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