Analysis by: Mark Joseph Manahan
ALIASES:

Perl/Shellbot.B trojan (Eset), Backdoor:Perl/Shellbot.S (Microsoft), Perl/Shellbot (McAfee)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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 connects to Internet Relay Chat (IRC) servers. It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 15,763 bytes
File Type: Script
Memory Resident: Yes
Initial Samples Received Date: 24 Sep 2013
Payload: Connects to URLs/IPs

Arrival Details

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

  • ftp://{BLOCKED}.{BLOCKED}.152.37/gj.exe

Backdoor Routine

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

  • {BLOCKED}.{BLOCKED}.75.200:8443

It executes the following commands from a remote malicious user:

  • TCP Flooding
  • UDP Flooding
  • HTTP Flooding
  • Scan for unpatched Websites (via google)
  • Remote Shell Command

It posts the following information to its command and control (C&C) server:

  • Opened Ports

  SOLUTION

Minimum Scan Engine: 9.300

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.KO. 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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