Analysis by: Jemimah Mae Molina

ALIASES:

Linux/Gafgyt.rhapr (ANTIVIR); ELF/Gafgyt.BV!tr (FORTINET)

 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 is an updated Bashlite malware designed to add infected internet-of-things devices to a distributed-denial-of-service (DDoS) botnet.

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: 138,335 bytes
File Type: ELF
Memory Resident: No
Initial Samples Received Date: 25 Mar 2019
Payload: Connects to URLs/IPs, Compromises system security, Downloads files

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 the C&C
  • ECHOSCAN – telnet scanner
  • OELINUX123 – similar to ECHOSCAN, but targets embedded systems
  • CFBYPASS – bypasses CloudFare Protection
  • BRICKER – downloads and executes bricker
  • MINER - downloads and executes miner
  • PKILL - kills a specified process
  • GRENADE – launches all DDOS module
    • JUNK - send randomly generated strings
    • UDP - send UDP packets
    • ACK - send ACK packets
    • VSE - send spoofed queries and/or connection attempts
    • TCP - send TCP packets
    • OVH - flood OVH an anti-DDoS web service

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

    The dropped binary saves its downloaded file using the following name:
    • hakai

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.894.06
FIRST VSAPI PATTERN DATE: 25 Mar 2019
VSAPI OPR PATTERN File: 14.895.00
VSAPI OPR PATTERN Date: 26 Mar 2019

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