Kaspersky Threats

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: Net-Worm

Net-Worms propagate via computer networks. The distinguishing feature of this type of worm is that it does not require user action in order to spread. This type of worm usually searches for critical vulnerabilities in software running on networked computers. In order to infect the computers on the network, the worm sends a specially crafted network packet (called an exploit) and as a result the worm code (or part of the worm code) penetrates the victim computer and activates. Sometimes the network packet only contains the part of the worm code which will download and run a file containing the main worm module. Some network worms use several exploits simultaneously to spread, thus increasing the speed at which they find victims.

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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

Worm.Win32.Padobot.a (also known as Korgo) spreads throughout the Internet using a vulnerability in Microsoft Windows LSASS. A description of the vulnerability can be found in Microsoft Security Bulletin MS04-011

The worm is written in C++ and is approximately 10KB in size, packed using UPX.

Propagation

When launching, the worm copies itself to the Windows system directory under a random name, and registers this file in the system registry auto-run key:

[HKLMSOFTWAREMicrosoftWindowsCurrentVersionRun]
   WinUpdate = %system%name of file

It also creates a registry key

 HKLMSOFTWAREMicrosoftWireless
  Server = 1

It creates the mutexes "10", "u2" and "uterm5" to flag its presence in the system.

The worm chooses the IP-addresses of random machines to infect and attack, similar to other worms which exploit the same LSASS vulnerability.

Other

Once infected, a victim machine will display an error message that the LSASS service has failed. After this error message has been displayed, the computer may reboot.

The worm open TCP ports 113, 3067 and 2041 to receive commands.

It attempts to connect to several IRC channels:

moscow-advokat.ru
 graz.at.eu.undernet.org
 flanders.be.eu.undernet.org
 caen.fr.eu.undernet.org
 brussels.be.eu.undernet.org
 los-angeles.ca.us.undernet.org
 washington.dc.us.undernet.org
 london.uk.eu.undernet.org
 lia.zanet.net
 gaspode.zanet.org.za
 irc.kar.net

to receive commands and transmit data.

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

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