KASPERSKY LAB Kaspersky® SMTP-Gateway 5.0 for Linux/Unix ADMINISTRATOR'S GUIDE KASPERSKY® SMTP-GATEWAY 5.0 FOR LINUX/UNIX Administrator's Guide © Kaspersky Lab Ltd. http://www.kaspersky.com Revision date: August 2004 Contents CHAPTER 1. KASPERSKY® SMTP-GATEWAY 5.0..................................................... 6 1.1. Licensing policy ..................................................................................................... 7 1.2. Hardware and software requirements .................................................................. 7 1.3. Distribution kit ........................................................................................................ 8 1.4. Help desk for registered users .............................................................................. 9 1.5. Conventions........................................................................................................... 9 CHAPTER 2. APPLICATION DEPLOYMENT SCENARIOS...................................... 11 2.1. Application architecture ....................................................................................... 11 2.2. How Kaspersky SMTP-Gateway works ............................................................. 12 2.3. Typical deployment scenarios............................................................................. 14 2.3.1. Installing the application at the network perimeter....................................... 15 2.3.2. Installing the application inside your mail system........................................ 17 CHAPTER 3. INSTALLING KASPERSKY ANTI-VIRUS SMTP-GATEWAY.............. 19 3.1. Installing Kaspersky SMTP-Gateway under Linux............................................. 19 3.2. Installing KAV SMTP-Gateway on a server running FreeBSD or OpenBSD ... 20 3.3. Installation steps .................................................................................................. 21 3.4. Configuring Kaspersky SMTP-Gateway............................................................. 22 CHAPTER 4. UNINSTALLING KASPERSKY SMTP-GATEWAY .............................. 25 CHAPTER 5. USING KASPERSKY SMTP-GATEWAY APPLICATION.................... 26 5.1. Updating anti-virus database .............................................................................. 26 5.1.1. Automatic anti-virus database updating....................................................... 28 5.1.2. Manual updating of the anti-virus database................................................. 28 5.1.3. Creating a shared directory for storing and sharing database updates...... 29 5.2. Anti-virus protection of email traffic ..................................................................... 30 5.2.1. Creating groups of recipients/senders ......................................................... 30 5.2.2. General message processing algorithm ...................................................... 33 5.2.3. Main tasks..................................................................................................... 35 5.2.3.1. Deliver messages without changes ...................................................... 35 5.2.3.2. Deliver only clean and disinfected messages....................................... 36 4 Kaspersky® SMTP-Gateway 5.0 5.2.3.3. Delete infected attachments.................................................................. 37 5.2.3.4. Replace infected attachments with messages created using templates................................................................................................. 38 5.2.4. Additional tasks............................................................................................. 38 5.2.4.1. Block messages delivery to recipients .................................................. 39 5.2.4.2. Deliver infected messages .................................................................... 40 5.2.4.3. Notify senders, administrator, and recipients........................................ 41 5.2.4.4. Filter messages by attachment types ................................................... 42 5.2.4.5. Backing up (quarantine, backup storage) ............................................. 43 5.2.4.6. Automatically add incoming and outgoing mail to archives.................. 44 5.3. Protection from hacker attacks and spam .......................................................... 45 5.4. Managing license keys........................................................................................ 46 5.4.1. Viewing information about license keys....................................................... 46 5.4.2. Renewing your license ................................................................................. 48 5.4.3. Removing a license key ............................................................................... 49 CHAPTER 6. ADVANCED SETTINGS ........................................................................ 50 6.1. Configuring anti-virus protection of mail traffic.................................................... 50 6.1.1. Scanning and disinfecting messages .......................................................... 50 6.1.2. iChecker technology ..................................................................................... 51 6.1.3. Setting up application timeouts .................................................................... 51 6.1.4. Setting performance restrictions .................................................................. 53 6.2. Setting up connection receiving interfaces ......................................................... 54 6.3. Setting up the routing table ................................................................................. 55 6.4. Managing the application .................................................................................... 56 6.5. Customizing date and time formats .................................................................... 58 6.6. Reporting options ................................................................................................ 58 CHAPTER 7. FREQUENTLY ASKED QUESTIONS................................................... 61 CHAPTER 8. TESTING APPLICATION OPERABILITY ............................................. 66 8.1. Testing the application using Telnet ................................................................... 66 8.2. Testing the application using EICAR .................................................................. 68 APPENDIX A. SUPPLEMENTARY INFORMATION ABOUT THE PRODUCT......... 70 A.1. Location of the application files in directories..................................................... 70 A.2. Kaspersky SMTP-Gateway configuration file .................................................... 74 A.3. Control signals for the smtpgw component........................................................ 86 Contents 5 A.4. Management files................................................................................................ 86 A.5. Application statistics............................................................................................ 87 A.6. Command line options for the smtpgw component ........................................... 92 A.7. Smtpgw return codes.......................................................................................... 93 A.8. Command line options for licensemanager ....................................................... 94 A.9. Kaspersky licensemanager return codes........................................................... 95 A.10. Keepup2date command line options ............................................................... 95 A.11. Keepup2date return codes ............................................................................... 96 A.12. Anti-virus scan information format.................................................................... 97 A.13. Messages about actions applied to the message ........................................... 98 APPENDIX B. KASPERSKY LAB............................................................................... 101 B.1. Other Kaspersky Lab Products ........................................................................ 102 B.2. Contact Us......................................................................................................... 106 APPENDIX C. LICENSE AGREEMENT .................................................................... 107 CHAPTER 1. KASPERSKY® SMTP-GATEWAY 5.0 Kaspersky® SMTP-Gateway for Linux/Unix (hereinafter referred to as Kaspersky SMTP-Gateway or the application) is designed for processing and scanning SMTP mail traffic for viruses. The application is a full-featured mail relay (compliant with IETF RFC internet standards) that runs under Linux, FreeBSD and OpenBSD operating systems. Kaspersky SMTP-Gateway allows to perform the following functions: · · · · · · Scan email traffic for viruses, including attached files and message bodies. Detect infected, suspicious, corrupted, and password-protected attachments and message bodies. Disinfect infected objects detected in email messages by scanning. Provide additional email traffic filtering by names and MIME types of attachments and apply certain processing rules to the filtered objects. Maintain logs of all email messages sent and/or received by the application, if this is required by the internal security policy of the company; Provide protection against hacking attacks, block unwanted email messages, provide the functions of an open mail relay of unsolicited email messages; Limit the load on your server by configuring the application settings and SMTP parameters. Notify senders, recipients, and the administrator of messages containing infected, suspicious, or corrupted objects. Automatically place infected, suspicious, and corrupted objects to the quarantine or to the backup storage . Automatically update the anti-virus database from the Kaspersky Lab's update servers. · · · · The application detects and disinfects infected objects using the anti-virus database. During scans, the contents of each file are compared with the sample code of known viruses contained in the database. Kaspersky® SMTP-Gateway 5.0 7 Remember that new viruses appear every day. To keep your network constantly protected from the latest threats, we recommend that you update your anti-virus database every 3 hours. · Configure and manage Kaspersky SMTP-Gateway either from a remote location using Webmin web interface, or locally, using standard OS tools such as command line options, signals, by creating special command files or by modifying the configuration file of the application. Monitor the antivirus protection status and view the statistics and application logs. · 1.1. Licensing policy The licensing policy for Kaspersky SMTP-Gateway imposes limitations on the use of the product by the following criteria: · · Number of users protected by the application Email traffic (MB/day) Each type of licensing is also limited by a certain period (typically one year or two years from the date of purchase). You can purchase a license limited by one of the above criteria (for example, by the daily mail traffic). The application has slightly different configuration parameters, depending on the type of license you have purchased. Thus, if the license is issued for a certain number of users, you will have to create a list of addresses (domains) that will be protected by Kaspersky SMTP-Gateway. If the license allows protection of the limited amount of email traffic, the application can be configured to notify the administrator when the traffic volume reaches critical values and hence the license is about to expire. 1.2. Hardware and software requirements Minimum system requirements for normal operation of Kaspersky SMTPGateway are as follows: · Hardware requirements: · Intel Pentium® processor (Pentium III or Pentium 4 recommended) 8 Kaspersky® SMTP-Gateway 5.0 · · at least 128 B RAM 100 MB available space on your hard drive to install the application Note that the backup storage, quarantine, and logs of incoming and outgoing mail are not included in the hard disk space required. If your network security policy requires the use of the above features, extra disk space will be needed. · · at least 500 MB available space in the /tmp file system Software requirements: · One of the following operating systems: o o o Linux RedHat (version 7.3, 8.0 or 9.0), Linux SuSE (version 8.1, 8.2 or 9.0), or Linux Debian (version 3.0) FreeBSD versions 4.9 or 5.2.1 OpenBSD version 3.4 · · Perl interpreter, version 5.0 or higher (www.perl.org) to install the application. Webmin version 1.070 or higher (www.webmin.com) to install the remote administration module (optional). 1.3. Distribution kit You can purchase Kaspersky SMTP-Gateway either from our dealers (retail box) or online at one of our online stores (for example, www.kaspersky.com ­ follow the E-store link). The retai ...