PLATFORM:

Linux, Unix

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 574 bytes
File Type: Other
Memory Resident: No
Initial Samples Received Date: 02 Oct 2014
Payload: Downloads files

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

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

It saves the files it downloads using the following names:

  • /tmp/b.c

NOTES:

The downloaded file /tmp/b.c is a C source code.

It is compiled using GNU C Compiler (GCC) which is saved with the file name .d.

The compiled binary is detected as ELF_KAITEN.SM.

It downloads another file from the following URL:

  • http://{BLOCKED}host.us/bots/regular.bot

It saves the downloaded file using the following file name:

  • /tmp/sh

However, the URL is already inaccessible during analysis.

It performs self cleanup by deleting the following files:

  • /tmp/.a
  • /tmp/.b.c
  • /tmp/.c
  • /tmp/.d
  • /tmp/sh
  • /tmp/c

It creates contrab file /tmp/c that schedules the weekly download and execution of regular.bot

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.186.03
FIRST VSAPI PATTERN DATE: 02 Oct 2014
VSAPI OPR PATTERN File: 11.187.00
VSAPI OPR PATTERN Date: 03 Oct 2014

Scan your computer with your Trend Micro product to delete files detected as TROJ_BASHKAI.A. 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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