Zafi.C

Classification

Malware

Email-Worm

W32

Zafi.C, W32/Zafi.C@mm, I-Worm.Zafi.c

Summary

Zafi.C is a variant of the Zafi mass-mailing worm family. This worm sends email messages with infected attachments in several different languages.

The payload of Zafi.C is a Distributed Denial-of-Service attack against google.com, microsoft.com and www.miniszterelnok.hu.

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

System Infection

When the worm's file is run, it copies itself as 'svchost.com' to Windows System folder and creates a startup key for this file in the Registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"_svchost.con" = "%SystemDir%\svchost.com"
 

%SystemDir% represents the Windows System folder name, for example C:\Windows\System32 on Windows XP systems.

Another copy is created in the same directory as 'svchost.con'.

Zafi.C keeps its state information in the registry under

[HKEY_LOCAL_MACHINE\Software\Microsoft\UpdateZ3]
 

Email propagation

Zafi.C collects email addresses from Windows Address Book and different files (eg. HTM, TXT, MBX, etc). The worm composes the messages it sends based on complex rules in many different languages. The email attachments might have double extensions (composed from .DOC/.TXT and .EXE/.SCR).

Payload

The payload of Zafi.C is a Distributed Denial-of-Service attack against

google.com
microsoft.com
www.miniszterelnok.hu