Symantec Security Response - VBS.Biscuit.A@mm © 1995-2003 Symantec Corporation. All rights reserved. Legal Notices Privacy Policy VBS.Biscuit.A@mm Discovered on: September 26, 2003 Last Updated on: September 29, 2003 02:50:35 PM VBS.Biscuit.A@mm is a mass-mailing worm that sends itself as an attachment to the first 50 email addresses in the Microsoft Outlook Address Book. The email message will have the following characteristics: Subject: Adsl no problem!!! Attachments: Adsl_no_problem.pdf<184 spaces>.vbs The worm attempts to copy itself to both the local host and reachable remote network shares. It will copy itself to the root of the network share as Netlog.vbs. The worm will also copy the original worm filename to the following folders if it is able to copy netlog.vbs to the root of the share: \Windows\Menu Avvio\Programmi\Esecuzione automatica\ \Windows\startm~1\programs\startup\ \Windows\ \Windows\start menu\programs\startup\ \Win95\start menu\programs\startup\ On the 10th of every month, VBS.Biscuit.A@mm will display a pop-up message. Also Known As: Worm.Win32.Registra [KAV], VBS/Bisquit [McAfee] Type: Worm Infection Length: 13 KB Systems Affected: Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP Systems Not Affected: DOS, Linux, Macintosh, OS/2, UNIX Virus Definitions (Intelligent Updater) * September 26, 2003 Virus Definitions (LiveUpdate™) ** October 01, 2003 *Intelligent Updater definitions are released daily, but require manual download and installation. Click here to download manually. **LiveUpdate virus definitions are usually released every Wednesday. Click here for instructions on using LiveUpdate. Wild: Number of infections: 0 - 49 Number of sites: 0 - 2 Geographical distribution: Low Threat containment: Easy Removal: Moderate Threat Metrics Wild: LowDamage: MediumDistribution: Medium Damage Payload: Large scale e-mailing: Sends itself to the first 50 email addresses in the Microsoft Outlook Address Book. Distribution Subject of email: Adsl no problem!!! Name of attachment: Adsl_no_problem.pdf<184 spaces>.vbs Size of attachment: 13 kb Shared drives: Attempts to copy itself to remote machines. When VBS.Biscuit.A@mm is executed, it performs the following actions: Copies itself as: C:\MyPhoto.JPG.VBS C:\System.dat.vbs C:\Adsl_no_problem.pdf %Windir%\D4NG3.vbs %Windir%\index.html Note: %Windir% is a variable. The worm locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location. Creates the following files: %Windir%\WallPaper.html %Windir%\BasicUpdate.dll.vbs %Windir%\untitled.HTM C:\netlog.tmp C:\Of.txt Script.ini Adds the values: "Data" = "c:\System.dat.vbs" "WinMine" = "%Windir%\D4NG3.vbs" "WinSetBrowse" = "%Windir%\BasicUpdate.dll.vbs" to the registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run so that the worm runs when you start Windows. Adds the values: "OlkContactRefresh" = "0" "OlkFolderRefresh" = "0" "FirstRun" = "0" "UseOutlook" = "0" to the registry key: HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4 Adds the values: "Message Send HTML" = "1" "Compose Use Stationery" = "1" "Stationery Name" = "%Windir%\untitled.HTM" "Wide Stationery Name" = "%Windir%\untitled.HTM" to the registry key: HKEY_CURRENT_USER\Identities\" & %DUID% & "\Software\Microsoft\Outlook Express\5.0\Mail Note: %DUID% is a variable. The worm uses the value of the Default User ID in the registry key: HKEY_CURRENT_USER\Identities\Default User ID. Adds the value: "wallPaper" = "%Windir\wallPaper.html" to the registry key: HKEY_CURRENT_USER\Control Panel\desktop so that the desktop displays the following wallpaper: Adds the value: "Start Page" = "http:/ /www.sesso.com" to the registry key: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main so that the start page of Internet Explorer is set to www.sesson.com. Adds the values: "Account Name" = "mail.supereva.it" "Connection Type" = "0" "Make Available Offline" = "1" "IMAP Port" = "143" "IMAP Timeout" = "60" "IMAP Use LSUB" = "1" "IMAP Polling" = "1" "IMAP Svr-side Special Folders" = "1" "IMAP Sent Items Folder" = "Posta inviata" "IMAP Drafts Folder" = "Bozze" "IMAP Prompt for Password" = "0" "IMAP Dirty" = "0" "IMAP Poll All Folders" = "1" "HTTPMail Prompt for Password" = "0" "HTTPMail Polling" = "1" "ShowAdBar" = "1" "POP3 Server" = "mail.supereva.it" "POP3 User Name" = "mp3free1" "POP3 Password2" = "hex:01 02 6d 00 61 00 69 00 6c 00 2e 00 73 00 75 00 70 00 65 00 72 00 65 00 76 00 61 00 2e 00 69 00 74 00 34 00 42 00 44 00 37 00 31 00 46 00 45 00 30 00 00 00" "POP3 Use Sicily" = "0" "POP3 Port" = "110" "POP3 Timeout" = "60" "POP3 Skip Account" = "1" "POP3 Prompt for Password" = "0" "SMTP Server" = "mail.supereva.it" "SMTP Port" = "25" "SMTP Timeout" = "60" "SMTP Display Name" = "ss dd" "SMTP Email Address" = "mp3free1@supereva.it" "SMTP Split Messages" = "0" "SMTP Split Message Size" = "64" "=?SMTP Prompt for Password" = "0" to the registry key: HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\OMI Account Manager\Accounts\00000001 so that it creates a mail account mail.supereva.it in Microsoft Outlook. This may cause an existing mail account to be deleted or overwritten if one exists. On the 10th of every month, displays the following message: Searches for files that have these extensions: jpg jpeg dwg bak doc html xls mdb txt mp3 gif png htm and sets the attributes to Hidden. The worm also copies itself as the same filename and appends .vbs to the filename. Pings IP addresses from 192.168.0.0 to 255.255.255.255, and, if the host is reachable, copies itself to: \Windows\Menu Avvio\Programmi\Esecuzione automatica\ \Windows\startm~1\programs\startup\ \Windows\ \Windows\start menu\programs\startup\ \Win95\start menu\programs\startup\ Searches for C:\Of.txt and sends email messages to the first 50 entries in the Microsoft Outlook Address Book if it does not exist. The email message has the following characteristics: Subject: Adsl no problem!!! Message: Attachments: Adsl_no_problem.pdf <184 spaces>.vbs (13 KB) Note: VBS.Biscuit.A@mm may not complete its payload due to a bug in its code. In such cases, an error messge will be displayed. 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. The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines. Disable System Restore (Windows Me/XP). Update the virus definitions. Run a full system scan and delete all the files detected as VBS.Biscuit.A@mm. Delete the values that were added to the registry. For specific details on each of these steps, read the following instructions. 1. Disabling 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" 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. Updating 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. Scanning for and deleting the infected files 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." Run a full system scan. If any files are detected as infected with VBS.Biscuit.A@mm, click Delete. 4. Deleting the value from the registry WARNING: 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. Click Start, and then click Run. (The Run dialog box appears.) Type regedit Then click OK. (The Registry Editor opens.) Navigate to the key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run In the right pane, delete the values: "Data" = "c:\System.dat.vbs" "WinMine" = "%Windir%\D4NG3.vbs" "WinSetBrowse" = "%Windir%\BasicUpdate.dll.vbs" Navigate to the key: HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4 In the right pane, delete the values: "OlkContactRefresh" = "0" "OlkFolderRefresh" = "0" "FirstRun" = "0" "UseOutlook" = "0" Navigate to the key: HKEY_CURRENT_USER\Identities\" & %DUID% & "\Software\Microsoft\Outlook Express\5.0\Mail In the right pane, delete the values: "Message Send HTML" = "1" "Compose Use Stationery" = "1" "Stationery Name" = "%Windir%\untitled.HTM" "Wide Stationery Name" = "%Windir%\untitled.HTM" Navigate to the key: HKEY_CURRENT_USER\Control Panel\desktop In the right pane, delete the value: "wallPaper" = "%Windir\wallPaper.html" Navigate to the key: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main In the right pane, delete the value: "Start Page" = "http:/ /www.sesso.com" Navigate to the key: HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\OMI Account Manager\Accounts In the left pane, delete the subkey: "00000001" Exit the Registry Editor. Write-up by: Kevin Ha