Writing Custom Signatures, Rule Structure, 164 | McAfee 6.1 guide

AWriting Custom Signatures

This section describes the structure of custom signatures and provides information on how to write custom signatures for the various client platforms. Topics include:

Rule Structure

Windows Custom Signatures

Solaris Custom Signatures

Linux Custom Signatures

Rule Structure

Every signature contains one or more rules written in ANSI Tool Command Language (TCL) syntax. Each rule contains mandatory and optional sections, with one section per line. Optional sections vary according to the operating system and the class of the rule. Each section defines a rule category and its value. One section always identifies the class of the rule, which defines the rule’s overall behavior.

The basic structure of a rule is the following:

Rule {

SectionA value

SectionB value

SectionC value

...

}

Be sure to review the rules for writing strings and escape sequences in TCL before attempting to write custom rules. A quick review of any standard reference on TCL should ensure that you enter proper values correctly.

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McAfee 6.1 manual Writing Custom Signatures, Rule Structure, Basic structure of a rule is the following, 164

Contents

McAfee Host Intrusion Prevention Page McAfee Host Intrusion Prevention Copyright Contents IPS Policies General Policies 103 Frequently Asked Questions 160 Writing Custom Signatures 164 IntroducingPrevention Host Intrusion Changes from the previous release New featuresWhat’s new in this release Using this guide Audience Conventions This guide uses the following conventionsBold Condensed Example Getting product information Standard documentation Contact information Customer ServiceProfessional Services Signature rules IPS featureBasic Concepts Behavioral rules EventsReactions Exception rules Client firewall rules Firewall featureFirewall rules Client application blocking rules Application Blocking featureGeneral feature Policies and policy categories Policy managementPolicy enforcement Policy assignment locking Policy inheritance and assignmentPolicy ownership Deployment and management Preset protectionAdaptive and Learn mode Tuning Reports Using ePolicy Orchestrator „ Deploy Host Intrusion Prevention clients EPolicy Orchestrator console EPolicy Orchestrator console Policy management Assign Policies Installing the Host Intrusion Prevention server Host Intrusion Prevention operationsAssigning owners to policies Generating notifications Deploying Host Intrusion Prevention clients Viewing and working with client data Placing clients in Adaptive or Learn mode Configuring policies Policy viewing alerts Fine-tuning Active X control security warning Using Help Help navigation procedures Help in the user interface IPS Events/SignaturesIPS Exception Rules IPS Signature Rules IPS Policies Overview Host and network IPS signature rules Benefits of Host IPS Benefits of Network IPS Preset IPS policiesBehavioral rules To configure the IPS Options policy Configuring the IPS Options policyQuick access Click Apply To create a new IPS Options policyIPS Options dialog box appears Select the needed options Configuring the IPS Protection policy To configure the IPS Protection policy To create a new IPS Protection policy IPS Protection dialog box appears Select the type of reaction for each severity level To create a new IPS Rules policy Configuring the IPS Rules policyTo assign IPS Rules policies IPS Rules policy details Creating exception rules To create an exception To edit an exception rule Editing exception rulesYou can view and edit details of an existing exception To disable/enable an exception Enabling and disabling exception rulesDeleting exception rules Moving exception rules to another policy Signatures Types of signaturesHost signatures Custom host signatures Viewing signatures IPS Rules-Signatures tab To modify default signatures Modifying host and network signaturesCreating custom signatures To modify the view of signatures Using the wizard to create signatures To create signatures using the wizard Using the standard mode to create signatures To create a signature with the standard mode New Custom Signature-General tab Editing custom signatures Deleting custom signaturesTo use Standard Method To use Expert Method To edit a custom signature Application Protection Rules 11 Application Protection Rules analysis To create an application protection rule 12 IPS Rules-Application Protection Rules 13 New Trusted Application dialog box-General tab IPS Events Editing Application Protection RulesEnabling and disabling Application Protection Rules Deleting Application Protection Rules Viewing events To view IPS events To change the event view Configuring the event viewFiltering events Marking events To mark an event as readTo mark an event as unread To hide an event Marking similar events To mark similar events„ Agent „ Signatures „ User „ Process „ Severity Level Hidden To view event details Viewing event detailsCreating event-based exceptions and trusted applications To create an event-based exception To create an event-based trusted application To search for a related exception IPS Client RulesSearching for related exceptions Regular View To migrate client rules to an IPS Rules policy Click the Aggregate View tab on the IPS Client Rules tab Aggregated ViewTo aggregate client rules Search IPS Exception Rules To search for exceptions and manage the list of exceptions 22 Search IPS Exception Rules tab Firewall Policies HIP 6.0 rules HIP 6.1 rules Stateful packet inspection State tableStateful packet filtering How firewall rules work Ordering the firewall rule list How stateful filtering works Stateful filtering process Protocol Description of handling How stateful packet inspection worksStateful protocol tracking Firewall rule groups and connection-aware groups TCP Overview Firewall Learn and Adaptive modes Stateful filtering Quarantine policies and rules To migrate rules Preset Firewall policiesMigrating custom 6.0 firewall rules to 6.1 rules Configuring the Firewall Options policy To configure the Firewall Options policySelect For these settings Off McAfee Default Learn Create New Policy dialog box appears „ Select New Policy To create a Firewall Rules policy Configuring the Firewall Rules policyCreating new Firewall Rules policies Include Local Subnet Automatically selected Select this For this protection Policy Server Medium Server High Viewing and editing firewall rules Do any of the followingTo view and edit a firewall rule Add Policy or Duplicate Policy To create a firewall rule Select the appropriate settings Click OKCreating a new firewall rule or firewall group To create a new rule group Firewall Rule Group dialog box appearsTo create a connection-aware group Type a name for this group in the Name field To delete a firewall rule or group Deleting a firewall rule or groupTo add predefined rules To modify the view, do any of the following Viewing firewall client rulesTo view all firewall client rules To view aggregated firewall client rules To view details of an aggregated firewall rule Select New Policy Configuring the Quarantine Options policyTo configure the Quarantine Options policy Configuring the Quarantine Rules policy Quarantine Rules policy provides access forCreating new Quarantine Rules policies To create a Quarantine Rules policy Click Properties Viewing and editing quarantine rulesTo view and edit a quarantine rule Creating a new quarantine rule or group Deleting a quarantine rule or groupTo create a quarantine rule To delete a quarantine rule or group Application Blocking Policies Application creation Application hooking Preset Application Blocking policiesApplication Blocking feature contains two policy categories To apply an Application Blocking Options policy Configuring the Application Blocking Options policySelect this policy For these settings Off McAfee Default Application Blocking Options To create an Application Blocking Rules policy Configuring the Application Blocking Rules policyCreating new Application Blocking Rules policies Viewing and editing Application Blocking Rules To view and edit an application blocking rule Creating new Application Blocking Rules To create a new application blocking ruleApplication Rule dialog box appears 100 Deleting an application blocking rule Viewing application client rulesTo delete an application blocking rule To view all client application rules To view aggregated client application rules To view details of an aggregated client application rule General Policies Preset General policies General feature contains four policy categories Configuring Enforce Policies Configuring the Client UI policyTo change the policy setting Regular User Administrator User To configure a Client UI policyCreating and applying a Client UI policy Disconnected User Setting passwords 107 108 To create an administrator passwordClick the Advanced Options tab in the Client UI policy To provide tray icon control of Windows UI To create a time-based passwordTray icon control 110 Configuring the Trusted Networks policyTo configure trusted network options Select To do this Add EditRemove Include Local Subnet Configuring the Trusted Applications policy Creating and applying Trusted Applications policiesTo create a new policy Trusted Application tab appears Creating trusted applications To create a trusted application To disable/enable a trusted application Editing trusted applicationsEnabling and disabling trusted applications Deleting trusted applications Maintenance Fine-tuning a deploymentAnalyzing IPS events 115 Creating exception rules and trusted application rules Working with client exception rulesCreating and applying new policies For details on working with client rules, see Policy maintenance and tasks To view and reset broken inheritance below a specific nodePolicies tab Policy inheritance and assignment To copy and paste policy assignments of a node Click Copy policy assignments To view nodes where a policy is assigned Policy CatalogViewing policy information To view all policies that have been created Editing policy information To view the settings and owner of a policyTo view assignments where policy enforcement is disabled To edit a policy Running server tasks Directory GatewayEvent Archiver Property Translator Creating rules Setting up notifications for eventsHow notifications work Host Intrusion Prevention notifications 124 Report repository Running reportsPre-defined reports Report content control Host Intrusion Prevention reportsSummary information and details IPS Events Summary by Signature Signature IPS Event Summary by TargetNetwork Intrusion Summary by Source IP Top 10 Attacked Nodes for IPS Top 10 Triggered SignaturesBlocked Application Summary Filters on platform and signature type Initial View Drill Down Host Name Failed Quarantine UpdatesTop 10 Blocked Applications Checking in the update package To add update packages automaticallyUpdating From the Task type list, select Repository Pull To add update packages manually To run an update taskTo have a client request an update Updating clients Host Intrusion Prevention Client Windows client 133 System tray iconClient console Setting options Unlocking the client interfaceTo unlock the Host Intrusion Prevention interface To customize client options Error Reporting TroubleshootingShow tray icon Error Reporting Select For this Security Violations To set IPS logging optionsTo set Firewall logging options 137 AlertsIntrusion alerts To respond to a firewall Learn Mode alert Firewall alerts138 Has the Treat rule match as an intrusion option selected Application Blocking alerts „ The IP address that the traffic pretends to come from 140 Quarantine alertsSpoof Detected alerts 141 IP Spoof Detected Alert dialog box IPS Policy tab IPS Policy optionsTo customize IPS Policy options 142 IPS Policy exception rules Exception rules listTo edit the exception rules 143 Firewall Policy tab Firewall Policy optionsTo customize Firewall Policy options 144 145 Firewall Policy RulesFirewall rules list Application Policy tab Application Policy optionsTo customize Application Policy options 146 147 Application Policy rulesApplication rules list Blocked Hosts tab Blocked Hosts list148 Column What it shows Until removed To edit the Blocked Hosts list149 Application Protection tab Application Protection listThis list shows all monitored processes on the client 150 Activity Log tab Activity Log optionsTo customize Activity Log options 151 Activity Log list 152Select Create Sniffer Capture... McAfee Host Intrusion Prevention Options Troubleshooting Client installation issuesSolaris client Policy enforcement with the Solaris client Client operations issues Run this command To do this154 File/Directory Name Description 155 To stop a Solaris clientTo restart a Solaris client Linux client Policy enforcement with the Linux client Verifying the client is running File Name Description Troubleshooting tool 158 Run the command hipts agent off To stop a Linux clientTo restart a Linux client 159 Frequently Asked Questions What is a policy?What is the McAfee Default policy? 160 161 How do I view IPS events triggered by clients? How do I create an exception based on an IPS Event? How do I create custom signatures for an IPS Policy? How do I find existing policies that match a given profile? Writing Custom Signatures Rule StructureBasic structure of a rule is the following 164 Section Name Value Description Mandatory common sections165 Use of Include and Exclude Name/domain user name Use of the dependencies section Optional common sectionsSection value variables Use of wildcards Use of environment variablesUse of predefined variables Windows IIS Web Server 169 MS SQL Database ServerSolaris Apache and iPlanet This topic describes how to write Windows custom signatures Windows Custom SignaturesClass Files 170 171 Advanced Details GUI name Explanation Class Isapi Machine where the client is installed in the manner host Windows Custom Signatures Class Registry 177 Class Services Section Values Meaning/remarks GUI Name Explanation Possible Values Windows Custom Signatures This topic describes how to write Solaris custom signatures Solaris Custom SignaturesClass UNIXfile 181 Relevant X directives per section Directive File Source File permission New permission 183 Advanced DetailsClass UNIXapache Solaris Custom Signatures Linux Custom Signatures 185 Summary of parameters and directives List of parameters according to typeList of directives according to type 186 Glossary 187 188 Blocked host 189 Console tree 190 EPolicy Orchestrator database server 191 See also minimal properties 192 Inactive agent 193 Policy enforcement interval 194 Severity level 195 SYN flood Index Working with clients Signatures, 46 creating, 48 creating custom Firewall policy tab rules List IPS Policy tab Page Mcafee.com