Parent class: VirWare

Viruses and worms are malicious programs that self-replicate on computers or via computer networks without the user being aware; each subsequent copy of such malicious programs is also able to self-replicate. Malicious programs which spread via networks or infect remote machines when commanded to do so by the “owner” (e.g. Backdoors) or programs that create multiple copies that are unable to self-replicate are not part of the Viruses and Worms subclass. The main characteristic used to determine whether or not a program is classified as a separate behaviour within the Viruses and Worms subclass is how the program propagates (i.e. how the malicious program spreads copies of itself via local or network resources.) Most known worms are spread as files sent as email attachments, via a link to a web or FTP resource, via a link sent in an ICQ or IRC message, via P2P file sharing networks etc. Some worms spread as network packets; these directly penetrate the computer memory, and the worm code is then activated. Worms use the following techniques to penetrate remote computers and launch copies of themselves: social engineering (for example, an email message suggesting the user opens an attached file), exploiting network configuration errors (such as copying to a fully accessible disk), and exploiting loopholes in operating system and application security. Viruses can be divided in accordance with the method used to infect a computer:
  • file viruses
  • boot sector viruses
  • macro viruses
  • script viruses
Any program within this subclass can have additional Trojan functions. It should also be noted that many worms use more than one method in order to spread copies via networks.

Class: Email-Worm

Email-Worms spread via email. The worm sends a copy of itself as an attachment to an email message or a link to its file on a network resource (e.g. a URL to an infected file on a compromised website or a hacker-owned website). In the first case, the worm code activates when the infected attachment is opened (launched). In the second case, the code is activated when the link to the infected file is opened. In both case, the result is the same: the worm code is activated. Email-Worms use a range of methods to send infected emails. The most common are: using a direct connection to a SMTP server using the email directory built into the worm’s code using MS Outlook services using Windows MAPI functions. Email-Worms use a number of different sources to find email addresses to which infected emails will be sent: the address book in MS Outlook a WAB address database .txt files stored on the hard drive: the worm can identify which strings in text files are email addresses emails in the inbox (some Email-Worms even “reply” to emails found in the inbox) Many Email-Worms use more than one of the sources listed above. There are also other sources of email addresses, such as address books associated with web-based email services.

Read more

Platform: JS

JavaScript (JS) is a prototype-based programming language. JavaScript has traditionally been implemented as an interpreted language. The most common use is in web browsers, where it is used for scripting to add interactivity to web pages.


Technical Details

Nevezed is a worm virus spreading via Microsoft Outlook. The worm itself is a Java Script file about 4KB in size and written in Java.

During installation the worm copies itself to the Windows system StartUp directory under the name "StartUp.js" and the Windows System directory under the name "CmdWsh32.js". It them registers this later file in the system registry as a java-class file. The worm also creates a backup copy of itself in the root directory of other drives.

Spreading: Email
To send infected messages the worm uses MS Outlook to send messages to all the addresses found in a victim's Outlook address book.

Infected messages sent by the worm have various subject titles. Possible subject titles could be:

Hello name
Hey name
Fwd: Hey You!
Fwd: Check this!
Fwd: Just Look
Fwd: Take a look!
Fwd: Loop at this!
Fwd: Check this out!
Fwd: It's Free!
Fwd: Look!
Fwd: Free Mp3s!
Fwd: Here you go!
Fwd: Have a look!
Look name!
Fwd: Read This!

Message body text is as follows:


Check out this great list of mp3 sites that I included in the attachments! I can get any Mp3 file that I want from these sites, and its free! And please don't be greedy! forward this email to all the people that you consider friends, and Let them benefit from these Mp3 sites aswell! Enjoy !

Infected messages contain one of following attachments:


Read more

Find out the statistics of the vulnerabilities spreading in your region on

Found an inaccuracy in the description of this vulnerability? Let us know!
Kaspersky Next
Let’s go Next: redefine your business’s cybersecurity
Learn more
New Kaspersky!
Your digital life deserves complete protection!
Learn more
Confirm changes?
Your message has been sent successfully.