Email-Worm

Classification

Malware

Email-Worm

W32

Type_vbs_mailer, @mm

Summary

This type of worm is embedded in an email attachment, and spreads using the infected computer's emailing networks.

Removal

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.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

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

An Email-Worm (also known as a mass-mailer or less commonly, an Internet worm) is a type of worm that distributes copies of itself in an infectious executable files attached to fake email messages.

For representative examples of email-worms, see:

Distribution

Email-Worm typically arrive as executable files attached to fake email messages.

Some mass mailers randomly compose the subjects and bodies of the messages from words and phrases carried in the worm's own code; other worms use content found in randomly selected files in the infected computer to compose the message. The name of the file attachment can be either random, or 'borrowed' from other files.

Many worms send themselves as attachments with double extension, for example .MPG.EXE or AVI.PIF. Often, a recipient will only notice the first extension listed and will try to open such attachments thinking, that they are multimedia files.

Execution

Email-worms normally use social engineering tactics to entice the user into opening and executing the email attachment. As such, users can avoid infection by an email-worm by simply refusing to open any email file attachments without first verifying its safety with the email sender.

In some cases however, an infected attachment may contain an exploit that allows the email worm to install and start automatically on the computer, without any user action. This is only possible if the email client contains certain vulnerabilities.

Payload

Most worms nowadays include malicious routines (e.g., password or data stealing) or carry viruses and backdoors that they can install on a victim's machine.