Analysis by: Karen Ivy Titiwa
ALIASES:

Gen:Variant.Trojan.Linux.Mirai.3(BITDEFENDER); Trojan.Linux.Mirai(IKARUS)

 PLATFORM:

Linux

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This Backdoor 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 a website to send and receive information.

It downloads a file from a certain URL then renames it before storing it in the affected system.

  TECHNICAL DETAILS

File Size: 137,980 bytes
File Type: ELF
Memory Resident: Yes
Initial Samples Received Date: 21 Jul 2020
Payload: Connects to URLs/IPs, Downloads files, Compromises system security

Arrival Details

This Backdoor 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 Backdoor adds the following processes:

  • ./zyxel zyxel.exploit
  • ./FuckinToaster.mpsl asus.exploit
  • ./FuckinToaster.mpsl linksys.exploit

Backdoor Routine

This Backdoor connects to the following websites to send and receive information:

  • http://{BLOCKED}.{BLOCKED}.53.27

Download Routine

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

  • http://{BLOCKED}.{BLOCKED}.53.27/Scylla.sh
  • http://{BLOCKED}.{BLOCKED}.53.27/FuckMalwareResearchers/FuckinToaster.mpsl

It downloads files from the following URLs then renames them before storage in the affected system:

  • /tmp/Scylla.sh
  • /var/tmp/Scylla.sh

It saves the files it downloads using the following names:

  • thonkphp
  • scylla.sh

Other Details

This Backdoor takes advantage of the following exploit(s):

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 16.118.04
FIRST VSAPI PATTERN DATE: 22 Jul 2020
VSAPI OPR PATTERN File: 16.119.00
VSAPI OPR PATTERN Date: 23 Jul 2020

Scan your computer with your Trend Micro product to delete files detected as IoT.Linux.MIRAI.VWIUR. 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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