Analysis by: Wilbert Luy
ALIASES:

HEUR:Backdoor.Linux.Mirai.h (Kaspersky), Backdoor:Linux/DemonBot.YA!MTB (Microsoft)

 PLATFORM:

Linux

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This backdoor is seen propagating via CVE-2018-18636, a cross-site scripting vulnerability affecting the wireless router D-Link DSL-2640T. This malware is capable of receiving commands to flood other systems.

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 executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 62,028 bytes
File Type: ELF
Memory Resident: Yes
Initial Samples Received Date: 19 Aug 2019
Payload: Connects to URLs/IPs, Collects system information, Others

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.

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • UDP - UDP flood
  • TCP - TCP flood
  • HEX - UDP HEX flood
  • STOP - STOP bot operation

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • 5.{BLOCKED}.{BLOCKED}.216:41061

Other Details

This Backdoor does the following:

  • Checks for the following folder to know architecture:
    • /usr/bin/apt-get - Ubuntu
    • /usr/lib/portage - Gentoo
    • /usr/bin/yum - CentOS
    • /usr/share/YaST2 - OpenSUSE
    • /usr/local/etc/pkg - FreeBSD
    • /etc/dropbear/ - Dropbear
    • /etc/opkg - OpenWRT

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.880.05
FIRST VSAPI PATTERN DATE: 19 Mar 2019
VSAPI OPR PATTERN File: 14.881.00
VSAPI OPR PATTERN Date: 20 Mar 2019

Scan your computer with your Trend Micro product to delete files detected as Backdoor.Linux.BASHLITE.SMJC2. 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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