Analysis by: Jimelle Monteser
ALIASES:

BackDoor-JShell.b (NAI), JSP/WebShell.A (Authentium), JSP/WebShell.A (exact) (FPROT), Backdoor.Java.JSP (Ikarus)

 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:

  • In the wild: Yes

  OVERVIEW

This backdoor may arrive bundled with malware packages as a malware component. It may be hosted on a website and run when a user accesses the said website.

It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size: Varies
File Type: JS
Initial Samples Received Date: 04 Oct 2013

Arrival Details

This backdoor may arrive bundled with malware packages as a malware component.

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

Other Details

This backdoor requires its main component to successfully perform its intended routine.

NOTES:

This malware uses JShell script codes which can be used to send commands to affected systems.

It may perform its malicious routines by connecting to certain URLs. These URLs depend on the following parameters passed on to it by its components:

  • action
  • btnNewDir
  • btnNewFile
  • cfAction
  • cmd
  • curPath
  • dbAction
  • dbname
  • dbPassword
  • dbPort
  • dbServer
  • dbType
  • dbUsername
  • dir
  • dstPath
  • encode
  • file
  • file2
  • fileContent
  • fileName
  • filesDelete
  • folderName
  • password
  • path
  • sessionTime
  • sql
  • tabID
  • textFileTypes

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 10.318.07
FIRST VSAPI PATTERN DATE: 05 Oct 2013
VSAPI OPR PATTERN File: 10.319.00
VSAPI OPR PATTERN Date: 05 Oct 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 JS_WEBSHELL.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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