Analysis by: Janus Agcaoili
ALIASES:

Linux.Xorddos (Symantec), HEUR:Trojan-DDoS.Linux.Znaich.a (Kaspersky), ELF/DDoS.G!tr (Fortinet)

 PLATFORM:

Linux, Unix

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 1,312,420 bytes
File Type: ELF
Initial Samples Received Date: 21 Oct 2015

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.

Installation

This Trojan drops the following file(s)/component(s):

  • /etc/cron.hourly/cron.sh
  • /etc/init.d/{random string}
  • /etc/rc{random number}.d/S90{random string}
  • /etc/rc2.d/S77{random string}
  • /etc/rc3.d/S77{random string}
  • /etc/rc4.d/S77{random string}
  • /etc/rc5.d/S77{random string}

Other Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.126.64:80
  • {BLOCKED}.{BLOCKED}.178.112:8005
  • {BLOCKED}.{BLOCKED}.122.105:90

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 11.994.05
FIRST VSAPI PATTERN DATE: 21 Oct 2015
VSAPI OPR PATTERN File: 11.995.00
VSAPI OPR PATTERN Date: 22 Oct 2015

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