Article submitted by: April Matthews
For more information: http://www.symantec.com/avcenter/

W32.Netsky.AB@mm Discovered on: April 27, 2004
Last Updated on: April 29, 2004 02:20:21 PM

W32.Netsky.AB@mm is a worm that scans for the email addresses on all non-CD-ROM drives on an infected computer. The worm then uses its own SMTP engine to send itself to the email addresses that it finds.

The email's Subject, Body, and attachment vary. The attachment has a .pif extension.Note:
• Symantec Consumer products that support Worm Blocking functionality automatically detect this threat as it attempts to spread.
• Symantec Security Response has developed a removal tool to clean the infections of W32.Netsky.AB@mm.

Also Known As:
W32/Netsky-AB [Sophos], W32/Netsky.ab@MM [McAfee], WORM_NETSKY.AB [Trend], Win32.Netsky.AB [Computer Associates], I-Worm.Netsky.ac [Kaspersky]
Variants:
W32.Netsky.AA@mm
Type:
Worm
.
7. The email has the following characteristics:
From: [spoofed]
Subject: (One of the following)
• Correction
• Hurts
• Privacy
• Password
• Wow
• Criminal
• Pictures
• Text
• Money
• Stolen
• Found
• Numbers
• Funny
• Only love?
• More samples
• Picture
• Letter
• Question
• Illegal

Body: (One of the following)
• Please use the font arial!
• How can I help you?
• Still?
• I've your password. Take it easy!
• Why do you show your body?
• Hey, are you criminal?
• Your pictures are good!
• The text you sent to me is not so good!
• True love letter?
• Do you have no money?
• Do you have asked me?
• I've found your creditcard. Check the data!
• Are your numbers correct?
• You have no chance...
• Wow! Why are you so shy?
• Do you have more samples?
• Do you have more photos about you?
• Do you have written the letter?
• Does it hurt you?
• Please do not sent me your illegal stuff again!!!

Attachment: (One of the following)
• corrected_doc.pif
• hurts.pif
• document1.pif
• passwords02.pif
• image034.pif
• myabuselist.pif
• your_picture01.pif
• your_text01.pif
• your_letter.pif
• your_bill.pif
• my_stolen_document.pif
• visa_data.pif
• pin_tel.pif
• your_text.pif
• loveletter02.pif
• all_pictures.pif
• your_letter_03.pif
• your_picture.pif
• abuses.pif

The worm attempts to use the infected computer's default DNS server to retrieve the IP address of the email server.
For example, if the email address is someone@hostname.com, it will attempt to retrieve the IP address of the server, hostname.com. If the worm fails, it will attempt to use one of the following DNS servers:
• 212.44.160.8
• 195.185.185.195
• 151.189.13.35
• 213.191.74.19
• 193.189.244.205
• 145.253.2.171
• 193.141.40.42
• 193.193.144.12
• 217.5.97.137
• 195.20.224.234
• 194.25.2.130
• 194.25.2.129
• 212.185.252.136
• 212.185.253.70
• 212.185.252.73
• 62.155.255.16
• 194.25.2.134
• 194.25.2.133
• 194.25.2.132
• 194.25.2.131
• 193.193.158.10
• 212.7.128.165
• 212.7.128.162Symantec Gateway Security 5400 Series and Symantec Gateway Security v1.0
• Antivirus component: An update for the Symantec Gateway Security AntiVirus engine to protect against the W32.Netsky.AB@mm worm is now available. Symantec Gateway Security 5000 Series users are advised to run LiveUpdate.
• IDS/IPS component: No update is currently planned for this worm.
• Full application inspection firewall component: By default when configure through the Policy Wizard, Symantec's full application inspection firewall technology protects against the propagation of the W32.Netsky.AB@mm worm by blocking infected systems from directly sending email to the Internet.
Symantec Enterprise Firewall 8.0
By default when configure through the Policy Wizard, Symantec's full application inspection firewall technology protects against the propagation of the W32.Netsky.AB@mm worm by blocking infected systems from directly sending email to the Internet.
Symantec Enterprise Firewall 7.0.x and Symantec VelociRaptor 1.5
By default when configure through the SMTP Wizard, Symantec's full application inspection firewall technology protects against the propagation of the W32.Netsky.AB@mm worm by blocking infected systems from directly sending email to the Internet.
Symantec Clientless VPN Gateway 4400 Series
Symantec Clientless VPN Gateway v5.0 is not affected by this threat. To reduce risk of further propagation you should also include a rule that only allows mail access from authenticated remote users to your internal mail server.
Symantec Gateway Security 300 Series
To reduce the risk of infection administrators are urged to use the AVpe feature of the SGS 300 series to make sure all their AV clients are up-to-date with their virus definitions.
Symantec Firewall/VPN 100/200 Series
To reduce the risk of further propagation, make sure you have a rule that only allows inbound/outbound mail to/from your mail server.

Symantec Security Response offers these suggestions on how to configure Symantec products in order to minimize your exposure to this threat.Symantec Gateway Security
• Run LiveUpdate on the appliance to obtain the latest virus definitions
• Configure your security policy to only allow inbound/outbound mail connections to/from from your internal mail server (this is done by default when configured through the Policy or SMTP Wizard)
• Turn on AV scanning in your SMTP inbound/outbound rules

Symantec Enterprise Firewall
• Configure your security policy to only allow inbound/outbound mail connections to/from from your internal mail server (this is done by default when configured through the Policy or SMTP Wizard)
• Offload AV scanning for all SMTP traffic

Symantec Clientless VPN
• Create a rule that only allows mail connections from the remote clients to the internal mail server.
• Make sure your users run LiveUpdate on all the end-user devices.

Symantec Gateway Security 300 Appliance
• Make sure that your security policy only allows inbound/outbound mail connections to/from from your internal mail server
• Configure the AV Policy Enforcement feature on your gateways to ensure that your Symantec Antivirus Corporate Edition and Symantec Client Security desktops are up-to-date with their virus definitions
• Run LiveUpdate on your desktop AV clients and have all your users do a full scan of their desktops

Symantec Firewall / VPN Appliance
• Make sure that your security policy only allows inbound/outbound mail connections to/from from your internal mail server
• Run LiveUpdate on your desktop AV clients and have all your users do a full scan of their desktops

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.
• 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 using the W32.Netsky.AB@mm Removal Tool
Symantec Security Response has developed a removal tool to clean the infections of W32.Netsky.AB@mm. This is the easiest way to remove this threat and should be tried first.
Manual Removal
The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
1. Disable System Restore (Windows Me/XP).
2. Update the virus definitions.
3. Restart the computer in Safe mode or VGA mode.
4. Run a full system scan and delete all the files detected as W32.Netsky.AB@mm.
5. Reverse the changes made to the registry.
For details on each of these steps, read the following instructions.
1. To disable System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.
Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.
Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.
For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:
• "How to disable or enable Windows Me System Restore"
• "How to turn off or turn on Windows XP System Restore"
Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable System Restore by following the instructions in the aforementioned documents.
For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools Cannot Clean Infected Files in the _Restore Folder," Article ID: Q263455.
2. To update the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
• Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
• Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).
The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.
3. To restart the computer in Safe mode or VGA mode
Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
• For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
• For Windows NT 4 users, restart the computer in VGA mode.
4. To scan for and delete the infected files
a. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
• For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
• For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan all files."
b. Run a full system scan.
c. If any files are detected as infected with W32.Netsky.AB@mm, click Delete.
5. To reverse the changes made to the registryWARNING: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry," for instructions.
a. Click Start, and then click Run. (The Run dialog box appears.)
b. Type regedit
Then click OK. (The Registry Editor opens.) c. Navigate to the key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

d. In the right pane, delete the value:
"BagleAV"="%Windir%\csrss.exe" e. Exit the Registry Editor. f. Restart the computer in Normal mode. For instructions, read the section on returning to Normal mode in the document, "How to start the computer in Safe Mode."

Revision History:
• April 29, 2004: Added Symantec product specific references.
• April 28, 2004:
• Upgraded from Category 2 to Category 3 based on increased rate of submissions.
• Updated with link to removal tool.

Write-up by: Ying Lin and Tony Lee

______________________

If you don't want to have to worry about this then please arrange to have the managed version of Corporate Edition of Norton Antivirus installed on your machine.

(This link tells you how to tell if you are a managed client. http://www.wnmu.edu/itdept/managedclient.htm)
By contacting the help desk at :
helpdesk@wnmu.edu
Ext. 4357
Online Help Request

http://www.wnmu.edu/itdept/help/helprequest.htm