Analysis by: Mark Joseph Manahan
ALIASES:

Mal/PerlBot-A (Sophos)

 PLATFORM:

Unix, Linux, Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This malware is an IRC (Internet Relay Chat) bot that leverages the Bash bug vulnerability, also known as Shellshock.

To get a one-glance comprehensive view of the behavior of this Backdoor, refer to the Threat Diagram shown below.

This backdoor connects to Internet Relay Chat (IRC) servers.

  TECHNICAL DETAILS

File Size: 55,947 bytes
File Type: Script
Memory Resident: Yes
Initial Samples Received Date: 27 Sep 2014
Payload: Compromises system security, Connects to URLs/IPs

Arrival Details

This backdoor may be downloaded from the following remote site(s):

  • http://{BLOCKED}.{BLOCKED}.85.69/ec.z via Shellshock Exploit

Backdoor Routine

This backdoor connects to any of the following Internet Relay Chat (IRC) servers:

  • {BLOCKED}s.bot.nu

It joins any of the following IRC channel(s):

  • #bash

It accesses a remote Internet Relay Chat (IRC) server where it receives the following commands from a remote malicious user:

  • UDP Flooding
  • TCP Flooding
  • Http Flooding
  • Irc Control (join,part,xejoin,op,deop,voice,devoice,nick,msg,quit,xaw,die)
  • Irc Channel (CTCP, Message, Notice Flooding)
  • Connect to arbitrary ip and port
  • Download arbitrary file
  • Scan port of certain IP
  • Mail Function
  • Resolve DNS' Ip
  • Ping IP:Port

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.176.04
FIRST VSAPI PATTERN DATE: 27 Sep 2014
VSAPI OPR PATTERN File: 11.177.00
VSAPI OPR PATTERN Date: 27 Sep 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

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


Did this description help? Tell us how we did.