NetSky.W, W32/Netsky.W@mm, I-Worm.Netsky.o


NetSky.W worm variant was discovered on April 16th, 2004.Although it has been just discovered, this variant is much more similar to NetSky.P or NetSky.Q than to any of the later variants. In fact, its structure bears a striking resemblance to that of NetSky.P, so only some differences among them will be listed on this description.This variant does not spread through P2P networks, as NetSky.P does.

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Suspect a file is incorrectly detected (a False Positive)?

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

For more Support


Find the latest advice in our Community.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

Installation to system

Upon execution Netsky.W copies itself as VisualGuard.exe file to the Windows folder. The worm adds a startup key for itself into System Registry:

"NetDy" = "%WinDir%\VisualGuard.exe"

where %WinDir% represents Windows folder name.

Additionally the worm drops the following files into Windows folder:


Email Spreading

Most of the email spreading functionality is similar or identical to NetSky.P.

Deleting Registry keys and disinfecting Bagle worm

NetSky.W worm removes Registry keys of several Bagle worm variants if it finds them on an infected computer.