Class
Worm
Platform
Win32

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: Worm

Worms spread on computer networks via network resources. Unlike Net-Worms, a user must launch a Worm in order for it to be activated. This kind of worm searches remote computer networks and copies itself to directories that are read/write accessible (if it finds any). Furthermore, these worms either use built-in operating system functions to search for accessible network directories and/or they randomly search for computers on the Internet, connect to them, and attempt to gain full access to the disks of these computers. This category also covers those worms which, for one reason or another, do not fit into any of the other categories defined above (e.g. worms for mobile devices).

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Platform: Win32

Win32 is an API on Windows NT-based operating systems (Windows XP, Windows 7, etc.) that supports execution of 32-bit applications. One of the most widespread programming platforms in the world.

Description

Technical Details

This is a network worm spreading over local and global networks. To spread, the worm connects to remote computers, and if the disk is shared for full access, the worm copies itself there to the Windows startup directory (if it exists).

The worm also has password stealing ability. It obtains RAS information (user mame, phone numbers, passwords), as well as cached passwords and sends them to two e-mail the addresses of krenx@mail.ru and winam@mail.ru.

The worm itself is a Win32 application (PE EXE file) written in Delphi and compressed with ASpach PE EXE compression utility. The worm body contains the following text:

SharedWorm v1.2

When the worm is run, it copies itself to the Windows system directory using three names: MSTASK.EXE, MSGSRV16.EXE, TAPI32.EXE, and registers these files in the following Registry auto-run keys:

HKCU\SOFTWAREMicrosoftWindowsCurrentVersionRun
HKLM\SOFTWAREMicrosoftWindowsCurrentVersionRun
HKLM\SOFTWAREMicrosoftWindowsCurrentVersionRunServices

So, the worm is run each time Windows is restarted.

The worm then connects to Web page "http://krenx.newmail.ru/ip.txt", and reads its contents. That page contains a list of subnet IP addresses. There are three numbers in the address instead of four IP address numbers, for example:

194.135.175.
213.24.179.
195.209.191.
213.59.57.

The worm then randomly selects one of these subnet "masks", and tries to connect to each machine in the subnet. If connection succeeds, the worm tries to access that computer hard drive disk files, then locates the name of the Windows directory on that computer and copies itself to there with the following name:

Start MenuProgramsStartUpAVPMonitor.exe

So, the worm copy is placed to the Windows auti-start directory, and is activated upon the next Windows restart.

The worm also is able to update itself from an Internet site. It obtains the Internet file "http://krenx.newmail.ru/win.exe", copies it to the local machine and runs it.

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

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