Analysis by: Karl Dominguez
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This malware has received attention from independent media sources and/or other security firms.

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

This Trojan may be unknowingly downloaded by a user while visiting malicious websites. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 33,280 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 17 Sep 2010
Payload: Downloads files

Arrival Details

This Trojan may be unknowingly downloaded by a user while visiting malicious websites.

However, as of this writing, the said sites are inaccessible.

Installation

This Trojan drops the following copies of itself into the affected system:

  • %System Root%\explored.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
Recycler = %System Root%\explored.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Recycler = %System Root%\explored.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
Recycler = %System Root%\explored.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunServices
Recycler = %System Root%\explored.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunServicesOnce
Recycler = %System Root%\explored.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows\
load
Recycler = %System Root%\explored.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
SharedTaskScheduler
Recycler = %System Root%\explored.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Recycler = %System Root%\explored.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
Recycler = %System Root%\explored.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnceEx
Recycler = %System Root%\explored.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
Recycler = %System Root%\explored.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServicesOnce
Recycler = %System Root%\explored.exe

Download Routine

This Trojan accesses the following websites to download files:

  • nynx.{BLOCKED}1a.com

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.468.01
FIRST VSAPI PATTERN DATE: 17 Sep 2010
VSAPI OPR PATTERN File: 7.469.00
VSAPI OPR PATTERN Date: 17 Sep 2010

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and terminate files detected as TROJ_JORIK.ASD

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
    • Recycler = %System Root%\explored.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • Recycler = %System Root%\explored.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunServices
    • Recycler = %System Root%\explored.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunServicesOnce
    • Recycler = %System Root%\explored.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows\load
    • Recycler = %System Root%\explored.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\SharedTaskScheduler
    • Recycler = %System Root%\explored.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Recycler = %System Root%\explored.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • Recycler = %System Root%\explored.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx
    • Recycler = %System Root%\explored.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
    • Recycler = %System Root%\explored.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServicesOnce
    • Recycler = %System Root%\explored.exe

Step 4

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