Backdoor.Linux.BASHLITE.AMW

September 03, 2019
 Analysis by: Wilbert Luy
 ALIASES:

HEUR:Backdoor.Linux.Gafgyt.a (Kaspersky), DDoS:Linux/Lightaidra!rfn (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:

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

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

  TECHNICAL DETAILS

File Size:

150,889 bytes

File Type:

ELF

Memory Resident:

Yes

Initial Samples Received Date:

25 Mar 2019

Payload:

Connects to URLs/IPs

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:

  • PINGING - checks connection with C&C
  • ECHOSCAN OFF/ON - scan and infects telnet ports with weak credentials
  • OELINUX123 OFF/ON - similar to ECHOSCAN
  • CFBYPASS - bypasses CloudFlare Protection
  • HOLD - stops any DDOS module
  • GRENADE - launches all DDOS module
    • JUNK - sends randomly generated strings
    • VSE - sends spoofed queries and/or connection attempts
    • ACK - ACK flood
    • UDP - UDP flood
    • TCP - TCP flood
    • OVH - OVH flood an anti-DDOS web service
  • STD - Does the following routine/command
    • Bricker - downloads and executes bricker
    • MINER - downloads and exercutes miner
    • PKILL - kills a specified process

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

  • {BLOCKED}.{BLOCKED}.25.213:3437

Other Details

This Backdoor does the following:

  • It uses the following credentials to try to login to other machines:
    • Username:
      • root
      • admin
    • Password:
      • root
      • admin
      • admin123
      • huigu309
      • xc3511
      • vizxv
  • It is capable of dropping downloader binaries depending on the system architecture.
    The dropped binary accesses the following URL to download its payload:
    • {BLOCKED}.{BLOCKED}.185.250/hakai.{architecture}
      where {architecture} is any of the following:
      • arm
      • arm7
      • m68k
      • mips
      • mpsl
      • ppc
      • sh4
      • spc
      • x86
      • x86_64

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

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.298.04

FIRST VSAPI PATTERN DATE:

14 Aug 2019

VSAPI OPR PATTERN File:

15.299.00

VSAPI OPR PATTERN Date:

15 Aug 2019

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