Limitations, 128 | HP Host Intrusion Detection System (HIDS)

Templates and Alerts

Limitations

Limitations

This section describes the general limitations of all the templates. Template speciﬁc limitations are included in the respective template sections:

•None of the templates perform alert aggregation or ﬁlter out identical alerts that repeat over a given time period.

•None of the kernel ﬁle monitoring templates can ﬁlter alerts based on whether a ﬁle is local or remote (NFS).

•Kernel ﬁle monitoring templates, by design, do not detect that the contents of a ﬁle were modiﬁed.

•Templates do not ﬁlter alerts for ﬁles speciﬁed with relative pathnames. Files must be speciﬁed with resolved, full pathnames.

•A template that has the pathnames_to_watch property does not monitor changes to a ﬁle via a hard link unless the full pathname of the hard link itself is speciﬁed in the property. Likewise, for the pathnames_to_not_watch property, modiﬁcations to a ﬁle via a hard link are not ignored unless the full pathname of the hard link is speciﬁed in the property.

•Kernel ﬁle monitoring templates do not monitor changes to ﬁles via symbolic links. Therefore, full pathnames of symbolic links should be not be speciﬁed in the pathnames_to_watch and pathnames_to_not_watch properties unless the modiﬁcation of the symbolic link itself should [not] be monitored.

•Alerts that specify an UNKNOWN program will occur under the following conditions:

—The program is started before the HIDS surveillance schedule is started.

—The offending process terminates right after it has performed some action to cause an alert.

—HIDS generates the alert after the offending process has already been terminated.

128	Appendix A

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HP Host Intrusion Detection System (HIDS) manual Limitations, 128

Contents

Manufacturing Part Number J5083-90013 December HP-UX Host Intrusion Detection System Administrator’s GuideEdition Warranty Government License Trademarks Iii Conventions Contents System Manager Screen Schedule Manager Screen Vii Host Manager ScreenNetwork Node Screen Viii Preferences ScreenTemplates and Alerts Idsagent Command Idsadmin CommandAutomated Response Agent Conﬁguration File HP Software License TroubleshootingMessages Original SSLeay License HP Software License Terms Xii Overview Summary Documentation Why Do You Need Intrusion Detection? Loss of Financial AssetsLoss of Intellectual Property Loss of Computing Resources Who Are the Perpetrators? How Are These Threats Realized?Misplaced Trust Malicious Code Why Existing Tools Are Only Part of the Solution Excessive Privilege for Simple TasksBeing Used as a Springboard to Attack the Next Victim Firewalls Encryption Security Auditing Tools Where Does Intrusion Detection Fit In? What Is Intrusion Detection? What HP-UX Hids Does What HP-UX Hids Does Not Do HP-UX Hids Components Graphic Representation How the Components Interact to Detect Intrusions HP-UX Hids Components HP-UX Hids Secure Communications Detection TemplatesSurveillance Groups Surveillance Schedules Glossary of HP-UX Hids Terms Intrusion Detection Data Intrusion Detection SystemKernel Node Vulnerability System ManagerVirus Glossary of HP-UX Hids Terms Chapter Conﬁguration Conﬁguration Optional IntroductionRequired Setting Up the HP-UX Hids Secure Communications Overview of Procedures to Set Up Secure CommunicationsScript to Use Where Used End Product Create the X.509 Certiﬁcates $ IDSgenAdminKeys install $ IDSgenAgentCerts TIP Transport the Certiﬁcates Install the Keys on Each Host $ IDSimportAgentKeys /var/opt/ids/tmp/myhost1.tar.Z myadmin Conﬁguring a Multihomed Agent System Step Example $ nslookup large2 Conﬁguring a Multihomed Administration System To conﬁgure a multihomed administration system Edit the agent conﬁguration ﬁle for example Conﬁguring a Loopback System To conﬁgure a loopback system Working with Firewalls Conﬁguring PortsWorking with NIS Enabling Large Numbers of Agents Enabling Over 23 Agents Thread LimitsTo change the value of maxthreadproc Select Kernel Conﬁguration Select Conﬁgurable Parameters Enabling Over 20 Inbound Requests To view and change the value of tcpconnrequestmax Accessing Manpages Restricting PermissionsRuntime File Permissions Files Permissions Accessing Manpages Chapter Getting Started Getting Started Agents System Manager Set up hosts and run schedules Starting HP-UX Hids for the First Time See , Host Manager Screen, on Operations Screens Schedule ManagerHost Manager Network Node Basic Screen Actions Selecting Entries in ListsSearching Entries Sorting Entries Basic Screen Actions Chapter System Manager Screen System Manager Screen System Manager Screen Starting the HP-UX Hids System Manager Stopping the HP-UX Hids System ManagerTo start the HP-UX Hids System Manager To stop the HP-UX Hids System Manager Status Value Description On the System Manager ScreenStatus Field Values On the System Manager screen Getting the Status of Agent HostsTo get the status of agent hosts Resynchronizing Agent Hosts To resynchronize agent hosts Choose the Actions Activate Schedule menu item Activating a Schedule on Agent HostsTo activate a surveillance schedule on agent hosts Stopping Schedules on Agent Hosts To stop a surveillance schedule on agent hosts Starting HP-UX Hids Agents To start the agent To halt the agent locally on the agent host Halting HP-UX Hids AgentsTo halt agents remotely from the System Manager Accessing Other Screens Go to Schedule Manager ScreenGo to Host Manager Screen To go to the Schedule Manager screen Return to System Manager Screen Go to Network Node ScreenGo to Preferences Screen Accessing Other Screens Chapter Schedule Manager Screen Schedule Manager Screen Schedule Manager Creating a Surveillance Schedule To create a surveillance schedule Displaying the Schedule Manager Screen Closing the Schedule Manager ScreenTo display the Schedule Manager screen To close the Schedule Manager screen Conﬁguring Surveillance Schedules Creating a New Surveillance ScheduleCopying a Surveillance Schedule To create a new surveillance schedule Modifying a Surveillance Schedule To modify a surveillance schedule Choose File Save Selected Schedule As Renaming a Surveillance ScheduleTo rename a surveillance schedule To delete a surveillance schedule Deleting a Surveillance ScheduleUndoing and Redoing Changes Choose File Save Selected Schedule Saving a Surveillance ScheduleTo save a surveillance schedule Conﬁguring Surveillance Groups Creating a New Surveillance GroupCopying a Surveillance Group To create a new surveillance group Modifying a Surveillance Group To modify a surveillance group To rename a surveillance group Renaming a Surveillance GroupRename Surveillance Group Dialog To delete a surveillance group Deleting a Surveillance GroupSaving a Surveillance Group To change the value of a property in a detection template Conﬁguring Detection TemplatesModifying a Property Value In a Template Edit List Dialog To add a new value Suggested Best Practices 11Edit Dialog Edit Some Template Conﬁguration Guidelines Setting Surveillance Schedule Timetables Specifying When a Schedule Will Run To specify when a schedule will run Canceling Changes See Saving a Surveillance Schedule on Viewing Surveillance Schedule Details Viewing the Source of a Surveillance ScheduleRefreshing the Details Display To view the source of a surveillance schedule Clearing the Details Display Saving the Details DisplaySave Dialog To clear the display Predeﬁned Surveillance Schedules and Groups Predeﬁned Surveillance Schedules Predeﬁned Surveillance Schedules Host Manager Screen Host Manager Screen Managing Hosts Displaying the Host Manager Screen Closing the Host Manager Screen Adding New Hosts Adding a New Host ManuallyAdd Host Dialog To add a new host manually IP Address Host NameAddress ﬁeld Adding New Hosts from /etc/hosts Name ﬁeldHost Name and IP Address To add new hosts from /etc/hosts Adding New Hosts from a File Rules for Host Lists FilesOpen Dialog To add new hosts from a ﬁle Modifying a Host To modify a host entry Deleting Hosts To delete a host entry To enable or disable an agent host for monitoring Enabling and Disabling Hosts Managing Tags Add, modify or delete tags To add a tag To edit a tag To delete a tag Saving the Host List in a Different File Maintaining Host FilesSaving the Host List in the Current File Using an Alternate Host List File Using Multiple Host Files Maintaining Host Files Chapter Network Node Screen 100 Network Node Screen Opening a Network Node ScreenClosing a Network Node Screen To display the Network Node screen for an agent host Alerts Tab 102 HP-UX Hids Alerts What They Mean, What to Do 104 Errors TabHP-UX Hids Errors What They Mean, What to Do General Operations Selecting EntriesSelecting with the Mouse Simple Version Find Dialog Searching for the Next Unseen EntrySearching for a String To delete one or more alerts or errors Deleting an EntryMarking Entries as Seen or Unseen To search again Unseen 108 Saving a Log File Set Network Node screen from the System Manager screenSaving the Current Log File Set Saving a New Log File Set Save Dialog Box Press Ctrl-AExample Creating a New File Set Example Saving the File Set over Another File Set Open Dialog Box Opening a Log File SetLog File Rotation 112 Preferences Screen 114 Preferences Screen Option Default Description General PreferencesTo choosing Actions Status Poll from the System Manager 116 Actions Resync from the System Manager screen Column Name Default Description Browser PreferencesAlert Events Preferences 118 Error Events Preferences Column Default Description Name System Manager Subtab 120 Templates and Alerts Alerts LimitationsProperty Types Templates Attack Detected Alert Alert Severity Detection Template Alert SummaryTable A-1 Detection Templates 124 Appendix a 125 126 Unix Regular ExpressionsExamples Appendix a 127 Limitations 128 Template Property Types Type I Pathnames to Not Monitor Type II Pathnames/Programs Pairs 130 Type III UIDs Type IV UID Pairs 132 Type V Network TripletsType VI Time Strings Type VII Flags Type Viii Scalars Buffer Overﬂow Template 134 Name Type Default Value Execute on StackTable A-2 Template Properties Table A-3 Execute on Stack Alert Properties 136 Unusual Argument Length Table A-4 Unusual Argument Length Alert Properties Argument with Non-printable Character 138 Appendix a 139 140 Race Condition Template Table A-6 Template Properties 142 File Reference ModiﬁcationTable A-7 File Reference Modiﬁcation Alert Properties Appendix a 143 144 Privileged Setuid Script ExecutedTable A-8 Setuid Script Executed Alert Properties Appendix a 145 146 Modiﬁcation of Files/Directories TemplateTable A-9 Template Properties Properties 148 File Being Modiﬁed Table A-10 File Being Modiﬁed Alert Properties 150 Appendix a 151 152 Changes to Log File TemplateTable A-11 Template Properties Append-Only File Being Modiﬁed Table A-12 Append-Only File Being Modiﬁed Alert Properties 154 Creation of Setuid File Template Table A-13 Template PropertiesAlerts generated By this template 156 Setuid File CreatedTable A-14 Setuid File Created Alert Properties Appendix a 157 158 Creation of World-Writable File TemplateTable A-15 Template Properties World-Writable File Created Table A-16 World-writable File Created Alert Properties 160 Appendix a 161 162 Modiﬁcation of Another User’s File Template Table A-17 Template Properties 164 Non-owned File Being ModiﬁedTable A-18 Non-owned File Being Modiﬁed Alert Properties Appendix a 165 Limitations 166 Login/Logout Template Table A-19 Template Properties 168 Login/Logout Table A-20 Login/Logout Alert Properties 170 Successful su DetectedTable A-21 Successful su Detected Alert Properties Appendix a 171 172 Template How this template Repeated Failed Logins TemplateTable A-22 Template Properties 174 Failed Login AttemptsTable A-23 Failed Login Attempts Alert Properties Appendix a 175 Repeated Failed su Commands Template Repeated Failed su AttemptsTable A-24 Template Properties Table A-25 Repeated Failed Su Attempts Alert Properties Appendix a 177 Template Conﬁguration Syntax 178 Appendix a 179 180 Automated Response 182 General Guidelines Response Methods 184 How Automated Response Works in HP-UX Hids Alert ProcessSecurity checks Programming Notes Table B-1 Additional Arguments Passed to Response Programs 186 Appendix B 187 188 Table B-3 Environment Variables Set for Response ProgramsName Value Description Appendix B 189 Programming Guidelines Writing Perl vs. Shell Response ScriptsWriting Privileged Response Programs 190 Code for scriptA.sh Solution aCode Examples Solution B Code for privA programCode for PrivB program 192 Solution C 194 Code for privC programCode for scriptC.sh script #!/usr/bin/sh Sample Shell Script Alert Responses Sample Response ProgramsSample C Language Program Source Code Forwarding Information 196 Appendix B 197 Halting any further attacks 198 Appendix B 199 Preservation of evidence 200 Appendix B 201 Restoration of a known good state 202 OVO Enablement in HP-UX Hids HP OpenView Operations Smart Plug-In 204 Idsagent Command 206 Idsagent Command Synopsis Options Example 208 Idsadmin Command 210 Idsadmin Command Synopsis Startup Options Commands 212 Agent Conﬁguration File 214 Agent Conﬁguration File Forcing Active Agent to Reread Conﬁguration File Name Default Value Global ConﬁgurationTable E-1 Global Conﬁguration Variables 216 Data Source Process Conﬁguration Kernel Audit Data DSPTable E-2 DSP idskernDSP Parameters 218 Correlator Conﬁguration Variables Remote Communication ConﬁgurationTable E-3 220 Messages 222 Agent Messages Idsagent failed to reopen stderr in append mode Idsagent internal error in handling signature groupsIdsagent failed to initialize conﬁguration module Idsagent failed to start group Idsagent unable to setup Sigchld signal handler Idsagent unable to setup Sighup signal handlerIdsagent unable to setup signal handler Idsagent unable to setup Sigsegv signal handler Idsagent error trying to shutdown a process Idsagent failed to allocate memoryIdsagent failed to create schedule path ﬁlename Idsagent failed to execute correlator corr Idsagent internal error no correlator in PMStartProcesses Idsagent internal error occurred in PMStopGroupIdsagent failed to initialize schedule Idsagent failed to initialize schedule in crontab Idsagent not enough disk space to create schedule Idsagent not enough disk space to parse scheduleIdsagent not enough disk space to save conﬁg ﬁle Idsagent out of process table space Unable to open the response script directory dir Internal errorInternal error unknown state System Manager Messages Exception while opening ﬁle filename File Save Error Incomplete or Invalid Entry Data Entry ErrorInvalid Host State Unable to disable host Invalid Property Value value Property Value Error No more instances of searchstring found Find Error Only one property may be edited at a time Selection ErrorSearchstring not found Find Error Select Property to be edited Selection Error Select Surveillance Group Name to delete Selection Error Select Surveillance Group to copy Selection ErrorSelect Surveillance Schedule to copy Selection Error Select Surveillance Schedule to delete Selection Error Surveillance Schedule not selected Schedule Selection Error Following hosts are in an invalid state for this commandUnable to Overwrite filename File Save Error 234 Unknown Host unable to resolve IP Address IPaddress Unknown IP Address unable to resolve Host Name 236 Troubleshooting 238 Appendix G 239 240 TroubleshootingAgent and System Manager cannot communicate with each other Agent does not start on system boot $ /usr/sbin/kmtune -q enableidds Agent needs further troubleshooting To clean up the IDS message queuesAgent host appears to hang and/or you see message disk full 242 Agent does not start after installation Agents appear to be stuck in polling statusAlert date/time sort seems inconsistent Alerts are not being displayed in the alert browser Idsadmin needs installed agent certiﬁcates Buffer overﬂow triggers false positivesDuplicate alerts appear in System Manager 244 IDScheckInstall fails with a kmtune error IDSgenAdminKeys or idsgui quits early Large ﬁles in /var/opt/ids Log ﬁles are ﬁlling upNo Agent Available 246 SSH does not perform a clean exit after idsgent is started Schedule Manager timetable screen appears to hang 248 System Manager appears to hangSystem Manager does not start after idsgui is started IPFilter rules for HP-UX Hids Using HP-UX Hids with IPFilter and SecureShellUnknown program and arguments in certain alert messages How to allow the SecureShell daemon to forward X11 trafﬁc 250 Appendix G 251 252 HP Software License Appendix H 253 OpenSSL License 254 Original SSLeay License Appendix H 255 256 HP Software License Terms 258