W32.HLLW.Kazmor

SUMMARY

W32.HLLW.Kazmor is a worm that has backdoor Trojan capability, which allows a hacker to gain control of the compromised computer. W32.HLLW.Kazmor spreads across a local network using shared drives. The worm also attempts to spread across KaZaA file-sharing networks.

The worm disguises itself as movies, games, or porno-related programs, or as software files to trick KaZaA users into downloading the program and opening it. W32.HLLW.Kazmor is written in the Borland Delphi programming language.

Protection

• Virus Definitions (LiveUpdate™ Weekly) June 26, 2002
• Virus Definitions (Intelligent Updater) June 20, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low

Distribution

• Distribution Level: Medium
• Ports: Random
• Target of Infection: Shared Network Drives and KaZaA shared folder

TECHNICAL DETAILS

When W32.HLLW.Kazmor is executed, it does the following:

It copies itself as C:\%Windows%Windows.exe.

NOTE: %Windows% is a variable. The worm locates the Windows folder (by default this is C:Windows or C:Winnt) and copies itself to that location.

It adds the value

Windows      C:\%Windows%Windows

to the registry key

HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun

This causes the worm to run when you start Windows.

The worm then opens a randomly changed TCP/UDP port to connect to the hacker. This allows the hacker to remotely take control of the compromised computer. After the hacker has gained control, the hacker can:

• Launch an IP packets attack
• Send spoofed IP packets to hacker-chosen IP addresses
• Download files from the host computer
• Steal the host system information, such as passwords, OS version, computer name, CPU speed, and shared folder information
• Scan ports

How it spreads

The worm first attempts to create the VBscript file Msvxd.vbs. This .vbs file searches for shared network drives on randomly chosen IP addresses.

It copies itself to the following location on the shared drives:

WindowsStart MenuProgramsStartupReal Player.exe

The worm searches the Windows registry to locate the KaZaA shared folder. Other KaZaA users can download files from that location. The worm then copies itself into this folder using many different names that are chosen randomly from a list that the worm carries. Here are some examples:

• [tmd]star wars episode 2 - attack of the clones [1of1]
• jenna jameson - built for speed
• [DiVX] Lord of the rings
• [DiVX] Harry Potter and the sorcerors stone
• CKY3 - Bam Margera World Industries Alien Workshop
• cat attacks child
• PS1 Boot Disc
• Sony Play station boot disc
• How to hack websites
• AIM Account Stealer
• MSN Password Hacker and Stealer
• Hacking Tool Collection
• Windows XP
• macromedia flash 5.0
• DSL Modem Uncapper
• Internet and Computer Speed Booster
• ZoneAlarm Firewall
• Borland Delphi 6 Key Generator

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

REMOVAL

To remove this worm:

1. Update the virus definitions, run a full system scan, and delete all files that are detected as W32.HLLW.Kazmor.
2. Delete the value
   
   Windows      C:\%Windows%Windows
   
   from the registry key
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun

For details on how to do this, read the following instructions.

To scan with Norton AntiVirus and delete the infected files:

1. Obtain the most recent virus definitions. There are two ways to do this:
   • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
   • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
     
     Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
     
2. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files.
   • NAV Consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • NAV Enterprise products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
3. Run a full system scan.
4. Delete all files that NAV detects as W32.HLLW.Kazmor.

To remove the value from the registry:

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

1. Click Start, and then click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the following key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
4. In the right pane, delete the value:
   
   Windows      C:\%Windows%Windows
   
5. Click Registry, and click Exit.