Class
Virus
Platform
Java

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: Virus

Viruses replicate on the resources of the local machine. Unlike worms, viruses do not use network services to propagate or penetrate other computers. A copy of a virus will reach remote computers only if the infected object is, for some reason unrelated to the virus function, activated on another computer. For example: when infecting accessible disks, a virus penetrates a file located on a network resource a virus copies itself to a removable storage device or infects a file on a removable device a user sends an email with an infected attachment.

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Platform: Java

Java is a platform for developing and running programs written in the Java programming language.

Description

Technical Details

This is the first known virus infecting Java files (classes). It was found in August 1998. It is able to replicate itself only in case the access to disk files is allowed (the disk access Java functions are allowed), i.e. the infected file is run as native Java application, not as an applet. The virus is not able to replicate, if it is run under known browsers - the system will display a warning message and terminate the virus.

When the virus is run as the application, it gets the possibility to call disk access Java functions (files searching, opening, reading, writing, closing). By using these functions the virus runs its files searching and infection routines: it scans the current directory for not infected Java classes and infects them. While infecting the virus opens files as binary data files, reads headers and parses internal Java format.

Before running its infection routine the virus has to access its own code. That is necessary to do it because the virus has to copy this code to other Java files while infecting them. The virus is not able to access its code in the memory - there are no such functions in Java language, so it scans the current directory for its own file (host file), parses its format, scans the file for virus code and reads it.

The virus then searches for other Java classes (the files with .CLASS name extension), parses them, writes its code into the file and inserts a call to the main virus function to the main class routine.

The virus function has the Strange_Brew_Virus(), it was the reason to name the virus "StrangeBrew". The "Strange_Brew_Virus" string is also visible in infected files when looking at them by any text editor.

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Find out the statistics of the vulnerabilities spreading in your region on statistics.securelist.com

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