Anomaly, FortiGuard Center | Fortinet IPS specs


IPS overview and general configuration	Monitoring the network and dealing with attacks

Anomaly

The following log message is generated when an attack anomaly is detected:

Message ID:	73001
Severity:	Alert
Message:	attack_id=<value_attack_id> src=<ip_address> dst=<ip_address>
	src_port=<port_num> dst_port=<port_num>
	interface=<interface_name> src_int=<interface_name>
	dst_int=<interface_name> status={clear_session detected dropped
	reset} proto=<protocol_num> service=<network_service>
	msg="<string><[url]>"
Example:	2004-04-07 13:58:53 log_id=0420073001 type=ips subtype=anomaly
	pri=alert attack_id=100663396 src=8.8.120.254 dst=11.1.1.254
	src_port=2217 dst_port=25 interface=internal src_int=n/a dst_int=n/a
	status=reset proto=6 service=smtp msg="anomaly: syn_flood, 100 >
	threshold 10.[Reference: http://www.fortinet.com/ids/ID100663396]"
Meaning:	Attack anomaly message providing the source and destination
	addressing information and the attack name.
Action:	Get more information about the attack and the steps to take from the
	Fortinet Attack Encyclopedia in the FortiGuard Center. Copy and paste
	the URL from the log message into your browser to go directly to the
	signature description in the Attack Encyclopedia.

The FortiGuard Center

The FortiGuard Center combines the knowledge base of the Fortinet technical team into an easily searchable database. FortiGuard Center includes both virus and attack information. Go to http://www.fortinet.com/FortiGuardCenter/.

Search for attacks in the FortiGuard Attack Encyclopedia by any of the criteria shown in Figure 1.

Figure 1: Searching the FortiGuard Attack Encyclopedia

Type in the name or ID of the attack, or copy and paste the URL from the log message or alert email into a browser.

FortiGate IPS User Guide Version 3.0 MR7
01-30007-0080-20080916	13

Image 13

Fortinet IPS manual Anomaly, FortiGuard Center

Contents

E R G U I D E Trademarks Contents IPS sensors Protocol decodersDoS sensors SYN flood attacks FortiGate IPS Introduction Fortinet documentation About this documentDocument conventions 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 signature and anomaly settings When to use IPSDefault fail open setting Config ips global Set fail-open enable disable end Configuring logging and alert email Setting the buffer sizeMonitoring the network and dealing with attacks Controlling sessions Attack log messages Signature FortiGuard Center Anomaly Creating a protection profile that uses IPS sensors Using IPS sensors in a protection profileAdding protection profiles to firewall policies 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 Enable SettingsColumn 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 web-based manager Custom signature configurationAdding custom signatures using the CLI Command syntax pattern Custom signature fields Creating custom signaturesShows the valid characters for custom signature fields Attackid Custom signature syntaxName BufferOverflow Srcport Content keywords Keyword and value Description Deprecated, see pattern and context keywords Context uri Pattern GETPattern yahoo.com Context host Regex/mdelim PcreRegexdelimismxAEGRU Uri !uristr IP header keywords Keyword and Value Description Protocol tcp TCP header keywords Keyword and Value Description Tcpflags S,12 Tcpflags AP 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 Protocol decoder list Protocols Protocol decoder names Port Viewing the protocol decoder list Alldefaultpass AlldefaultIPS sensors Viewing the IPS sensor list Adding an IPS sensor Configuring IPS sensorsProtectclient Protectemailserver IPS sensor filters IPS sensor attributes Reset Configuring filtersIPS sensor overrides Delete and Edit Delete or edit the filter Icons Application Configuring pre-defined and custom overrides Source Exempt IP DoS sensors Viewing the DoS sensor list Configuring DoS sensorsSequence in which the sensors examine network traffic Appears, and select OK DoS sensor attributes Anomaly configurationName Enter or change the DoS sensor name Comments Will appear in the DoS sensor list Understanding the anomalies Udpflood Anomaly Description TcpdstsessionUdpscan Udpsrcsession Understanding the anomalies SYN flood attacks What is a SYN flood attack?How SYN floods work What is SYN proxy? What is SYN threshold?FortiGate IPS Response to SYN flood attacks 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 Icmp sweep attacks What is an Icmp sweep?How Icmp sweep attacks work FortiGate IPS response to Icmp sweep attacks Predefined Icmp signatures Icmp sweep anomalies Configuring Icmp sweep protection FortiGate Version 3.0 MR7 IPS User Guide Index Technical support