Analysis by: Francis Xavier Antazo
ALIASES:

a variant of Linux/Rekoobe.B (ESET); Linux/Rekoobe.A (AVG); ELF:Rekoob-C [Trj] (Avast);

 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: 49748 bytes
File Type: ELF
Memory Resident: Yes
Initial Samples Received Date: 28 Nov 2015

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:

  • Upload arbitrary file
  • Download file
  • Reverse Shell

Information Theft

This backdoor s configuration file contains the following information:

  • SECRET
  • MAGIC
  • PROXYHOST
  • PROXYPORT
  • USERNAME
  • PASSWORD
  • ENDPOINT
  • SERVER_PORT
  • CONNECT_BACK_DELAY

NOTES:

This malware requires any of the following configuration files for it to execute properly:

  • /usr/lib/libsagented.so.1
  • /usr/lib/libXcurl
  • /usr/lib/llib-llgrpc
  • /usr/lib/liboop-trl.so.0.0.0

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.192.01
FIRST VSAPI PATTERN DATE: 04 Dec 2015
VSAPI OPR PATTERN File: 12.193.00
VSAPI OPR PATTERN Date: 05 Dec 2015

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