Custom signature configuration | Fortinet IPS specification

Custom signature configuration

Custom signatures

Create New	Select to create a new custom signature.
Name	The custom signature name.
Signature	The signature syntax.
Delete icon	Select to delete the custom signature.
Edit icon	Select to edit the custom signature.

Custom signature configuration

Add custom signatures using the web-based manager or the CLI. For more information about custom signature syntax, see “Creating custom signatures” on page 23 and “Custom signature syntax” on page 24.

Adding custom signatures using the web-based manager

To add a custom signature

1Go to Intrusion Protection > Signature > Custom.

2Select Create New to add a new custom signature, or select the Edit icon to edit a custom signature.

Figure 5: Edit Custom Signature

3Enter a name for the custom signature.

4Enter the Signature.

5Select OK.

Adding custom signatures using the CLI

After adding the custom signature, configure the settings for it under the signature group named custom.

Command syntax pattern

config ips custom edit <name_str>

set signature <signature_str>

end

Keywords and variables	Description	Default

name_str	The name of the custom signature.
signature	Enter the custom signature.	No default.
<signature_str>

	FortiGate IPS User Guide Version 3.0 MR7
22	01-30007-0080-20080916

Image 22

Fortinet IPS Custom signature configuration, Adding custom signatures using the web-based manager, Command syntax pattern

Contents

E R G U I D E Trademarks Contents DoS sensors Protocol decodersIPS sensors SYN flood attacks Introduction FortiGate IPS Document conventions About this documentFortinet documentation Typographic conventions FortiGate Pptp VPN User Guide Fortinet Knowledge Center Customer service and technical supportComments on Fortinet technical documentation IPS settings and controls IPS overview and general configurationThis section contains the following topics Default fail open setting When to use IPSDefault signature and anomaly settings Config ips global Set fail-open enable disable end Monitoring the network and dealing with attacks Setting the buffer sizeConfiguring logging and alert email Controlling sessions Attack log messages Signature Anomaly FortiGuard Center Adding protection profiles to firewall policies Using IPS sensors in a protection profileCreating a protection profile that uses IPS sensors Select Create New Adding protection profiles to user groups Using IPS sensors in a protection profile IPS predefined signatures Predefined signaturesViewing the predefined signature list Column SettingsEnable Clear All Filters Create a sensor and add IPS filters to it Viewing the predefined signature list IPS custom signatures Custom signaturesViewing the custom signature list Adding custom signatures using the CLI Custom signature configurationAdding custom signatures using the web-based manager Command syntax pattern Custom signature fields Creating custom signaturesShows the valid characters for custom signature fields Name BufferOverflow Custom signature syntaxAttackid Srcport Content keywords Keyword and value Description Deprecated, see pattern and context keywords Pattern yahoo.com Pattern GETContext uri Context host RegexdelimismxAEGRU PcreRegex/mdelim Uri !uristr Protocol tcp IP header keywords Keyword and Value Description TCP header keywords Keyword and Value Description Tcpflags AP Tcpflags S,12 Icmp keywords Keyword and Value Usage UDP header keywords Keyword and Value DescriptionOther keywords Keyword and Value Description Example custom signatures Example 1 signature to block access to example.comSbid --name Block.example.com Sbid --name Block.example.com Sbid --name Block.SMTP.VRFY.CMD Example 2 signature to block the Smtp ‘vrfy’ commandSbid --name Block.SMTP.VRFY.CMD --pattern vrfy Creating custom signatures Protocol decoders Protocol decodersUpgrading the IPS protocol decoder list Viewing the protocol decoder list Protocol decoder list Protocols Protocol decoder names Port IPS sensors AlldefaultAlldefaultpass Viewing the IPS sensor list Protectclient Configuring IPS sensorsAdding an IPS sensor Protectemailserver IPS sensor attributes IPS sensor filters IPS sensor overrides Configuring filtersReset Delete and Edit Delete or edit the filter Icons Configuring pre-defined and custom overrides Application Exempt IP Source DoS sensors Sequence in which the sensors examine network traffic Configuring DoS sensorsViewing the DoS sensor list Appears, and select OK Name Enter or change the DoS sensor name Comments Anomaly configurationDoS sensor attributes Will appear in the DoS sensor list Understanding the anomalies Udpscan Anomaly Description TcpdstsessionUdpflood Udpsrcsession Understanding the anomalies SYN flood attacks What is a SYN flood attack?How SYN floods work FortiGate IPS Response to SYN flood attacks What is SYN threshold?What is SYN proxy? How IPS works to prevent SYN floods IPS operation before synflood threshold is reached Suggested settings for different network conditions Configuring SYN flood protectionConfigure the options for tcpsynflood Select OK How Icmp sweep attacks work What is an Icmp sweep?Icmp sweep attacks FortiGate IPS response to Icmp sweep attacks Predefined Icmp signatures Icmp sweep anomalies Configuring Icmp sweep protection Index FortiGate Version 3.0 MR7 IPS User Guide Technical support