Threat Descriptions

Donut

Classification

Category :

Malware

Type :

Virus

Platform :

W32

Aliases :

Donut, .NET virus, Dotnet

Summary

Donut is the first known virus implemented in the Microsoft C# and Microsoft Intermediate Language (MSIL). It targets binary files under Microsoft .NET architecture.

Sample of this virus was posted by the virus author directly to several anti-virus companies on January 9th, 2002.

Removal

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.

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 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.

Technical Details

The virus itself is very simple and will never become a real-world problem.

The Donut virus is 8kB long. When executed, it infects all other .NET executables with .EXE extension in the current directory and directories above it.

After this, there's a one-in-ten chance the virus will show a dialog box with this text: 

This cell has been infected by dotNET virus!
 .NET.dotNET by Benny/29A

The virus will then just exit. It doesn't stay in memory and will only spread further if an infected file is executed again.

The first fully .NET compliant operating system from Microsoft, known as 'Blackcomb', is estimated to ship in 2003.

Donut has not been found in the wild. It is not considered to pose any threat at the moment. Nevertheless, it's the first virus of its kind.