Analysis by: Rhena Inocencio
ALIASES:

Backdoor:PHP/Lollusc.A (Microsoft), PHP.Backdoor.Trojan (Symantec)

 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:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This backdoor may be hosted on a website and run when a user accesses the said website.

It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size: 3,146 bytes
File Type: Script
Initial Samples Received Date: 07 May 2013
Payload: Executes files, Compromises system security

Arrival Details

This backdoor may be hosted on a website and run when a user accesses the said website.

Backdoor Routine

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

  • Create File
  • Upload File
  • Execute Commands

NOTES:

This backdoor disguises itself as a GIF but actually contains a PHP script. This is installed in a compromised web server by a malicious user.

This backdoor would execute any encoded base64 command in the parameter osc.

The command is appended on the host site as follows:

  • &osc={encoded base64 command}

It will send the following e-mail message:

Ni Bos Link Nya: {Server Name} {Request URI}- IP Yang Gunain: {IP address} - Time: {current date - Hour:Minute:Seconds}

It will the send the message to the following e-mail addresses:

  • {BLOCKED}bh@gmail.com
  • {BLOCKED}dronesta@gmail.com
  • {BLOCKED}nshell@gmail.com

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.902.01
FIRST VSAPI PATTERN DATE: 07 May 2013
VSAPI OPR PATTERN File: 9.903.00
VSAPI OPR PATTERN Date: 08 May 2013

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

Close all opened browser windows

Step 3

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