Analysis by: Anthony Joe Melgarejo

 PLATFORM:

Linux, Unix

 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 may be downloaded by other malware/grayware from remote sites.

It joins an Internet Relay Chat (IRC) channel. It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 31,428 bytes
File Type: ELF
Memory Resident: Yes
Initial Samples Received Date: 02 Oct 2014
Payload: Connects to URLs/IPs, Compromises system security

Arrival Details

This backdoor may be downloaded by the following malware/grayware from remote sites:

  • TROJ_BASHLITE.A

It may be downloaded from the following remote sites:

  • http://www.{BLOCKED}er-services.name/b.c

Backdoor Routine

This backdoor connects to any of the following IRC server(s):

  • x.{BLOCKED}shellz.net:25

It joins any of the following Internet Relay Chat (IRC) channels:

  • #int
  • #pwn

It executes the following commands from a remote malicious user:

  • Perform PUSH-ACK flood
  • Perform SYN flood
  • Perform UDP flood with spoofed source address
  • Perform UDP flood without spoofed source address
  • Change nickname
  • Change server
  • Get spoofed source addresses
  • Set spoofed address subnet mask
  • Disable client
  • Enable client
  • Terminate client
  • Download file
  • Stop all attacks
  • Send raw IRC command
  • Start remote shell

NOTES:

It changes its process name to -bash and clears its command line.

The IRC nickname it uses is a randomly generated string.

It creates and locks the file /tmp/.z to ensure that only one copy of itself is running.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.180.05
FIRST VSAPI PATTERN DATE: 29 Sep 2014
VSAPI OPR PATTERN File: 11.181.00
VSAPI OPR PATTERN Date: 30 Sep 2014

Restart in normal mode and scan your computer with your Trend Micro product for files detected as ELF_KAITEN.SM. 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 this Knowledge Base page for more information.


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