Analysis by: Wilbert Luy
ALIASES:

HEUR:Backdoor.Linux.Gafgyt.a (Kaspersky), Trojan:Script/Oneeva.A!ml (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.

  TECHNICAL DETAILS

File Size: 128,317 bytes
File Type: ELF
Memory Resident: Yes
Initial Samples Received Date: 08 Aug 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:

  • TELNETSCANNER - SCANS and INFECT devices with weak credentials
  • FLOAD - TELNETSCANNER flood
  • UPDATE - download updated binary from C&C
  • HTTP - HTTP flood
  • CLOUDFLATE - HTTP flood with CLOUDFLARE protection bypass
  • DOMINATE - HTTP flood with DGA
  • CNC - set CNC
  • HOLD - STOP current flood
  • JUNK - SEND random strings
  • UDP - UDP flood
  • XMAS - XMAS flood
  • TCP - TCP flood
  • STD - STD flood
  • STOMP - STD, TCP and DOMINATE command
  • STOP - STOP bot

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

  • {BLOCKED}.{BLOCKED}.195.33:42516

Other Details

This Backdoor does the following:

  • It is capable of dropping downloader binaries depending on the system architecture.
    The dropped binary accesses the following URL to download its payload:
    • http://{BLOCKED}.{BLOCKED}.195.33/assailant.{architecture}
      where {architecture} is any of the following"
      • Mips
      • Mps1
      • Sh4
      • X86
      • Arm6
      • I686
      • Ppc
      • I586
      • M68k
      • Sparc
      • Arm4
      • Arm5
      • Arm7
      • ppc440fp

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.288.04
FIRST VSAPI PATTERN DATE: 09 Aug 2019
VSAPI OPR PATTERN File: 15.289.00
VSAPI OPR PATTERN Date: 10 Aug 2019

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