Analysis by: Christopher Daniel So


Trojan:Win32/Goriadu.A (Microsoft), Gen:Variant.Goriadu.3 (FSecure), Trojan.Win32.Goriadu (Ikarus)


Windows 2000, Windows XP, Windows Server 2003


  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes


This Trojan may be dropped by other malware.

It opens a hidden Internet Explorer window.

It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats.


File Size: 713,728 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 23 Dec 2010

Arrival Details

This Trojan may be dropped by the following malware:


Autostart Technique

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

PathName = "{malware path and file name}"

Other System Modifications

This Trojan adds the following registry keys:


Backdoor Routine

This Trojan opens a hidden Internet Explorer window.

Download Routine

This Trojan connects to the following malicious URLs:

  • http://u.{BLOCKED}
  • http://u.g{BLOCKED}
  • http://{BLOCKED}.{BLOCKED}.66.91-bj-cnc/UpdateSetting.asmx
  • http://www.{BLOCKED}{random number}
  • http://www.{BLOCKED}

Other Details

This Trojan does the following:

  • It accesses the above URLs through a hidden Internet Explorer window each time the computer connects to the Internet.


Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.721.00
VSAPI OPR PATTERN Date: 24 Dec 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

Delete this registry key

[ 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSock2
    • speednet_sph

Step 3

Scan your computer with your Trend Micro product and note files detected as TROJ_GORIADU.SMC

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Search and delete the file detected as TROJ_GORIADU.SMC

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_GORIADU.SMC. 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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