Chapter 7 Defining Signatures

Creating Custom Signatures

no—Removes an entry or selection setting.

regex-string—Specifies a regular expression to search for in a single TCP packet.

service-ports—Specifies the ports or port ranges where the target service may reside. The valid range is 0 to 65535. It is a separated list of integer ranges a-b[,c-d] within 0 to 65535. The second number in the range must be greater than or equal to the first number.

specify-exact-match-offset {yes no}—(Optional) Enables exact match offset:

exact-match-offset—Specifies the exact stream offset the regular expression string must report for a match to be valid. The value is 0 to 65535.

specify-min-match-length {yes no}—(Optional) Enables minimum match length:

min-match-length—Specifies the minimum number of bytes the regular expression string must match. The value is 0 to 65535.

strip-telnet-options {true false}—Strips the Telnet option characters from the data before the pattern is searched.

swap-attacker-victim {true false}—Swaps the attacker and victim addresses and ports (source and destination) in the alert message and in any actions taken. The default is false.

Creating a String TCP Engine Signature

To create a signature based on the String TCP engine, follow these steps:

Step 1 Log in to the CLI using an account with administrator or operator privileges.

Step 2 Enter signature definition submode.

sensor# configure terminal

sensor(config)# service signature-definition sig1

Step 3 Specify a signature ID and subsignature ID for the signature. Custom signatures are in the range of 60000 to 65000.

sensor(config-sig)# signatures 60025 0

Step 4 Enter signature description submode.

sensor(config-sig-sig)# sig-description

Step 5 Specify a name for the new signature. You can also specify a additional comments about the sig using the sig-commentcommand or additional information about the signature using the sig-string-infocommand.

sensor(config-sig-sig-sig)# sig-name This is my new name

Step 6 Exit signature description submode.

sensor(config-sig-sig-sig)# exit

Step 7 Specify the string TCP engine.

sensor(config-sig-sig)# engine string-tcp

Step 8 Specify the service ports.

sensor(config-sig-sig-str)# service-ports 23

Step 9 Specify the direction.

sensor(config-sig-sig-str)# direction to-service

 

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Cisco Systems IPS4510K9 manual Creating a String TCP Engine Signature

IPS4510K9 specifications

Cisco Systems has long been a leading player in network security, and its IPS (Intrusion Prevention System) series is a testament to its commitment to safeguarding digital environments. Among its notable offerings are the IPS4510K9 and IPS4520K9 models, both designed to provide advanced threat protection for mid-sized to large enterprise networks.

The Cisco IPS4510K9 and IPS4520K9 are distinguished by their cutting-edge features that help organizations defend against a myriad of cyber threats. These systems utilize a multi-layered approach to security, integrating intrusion prevention, advanced malware protection, and comprehensive visibility across the network.

One of the primary characteristics of the IPS4510K9 is its high performance. It boasts a throughput of up to 1 Gbps, making it suitable for environments that demand rapid data processing and real-time responses to threats. The IPS4520K9, on the other hand, enhances that capability with improved throughput of up to 2 Gbps, accommodating larger enterprises with heavier network traffic. These models are equipped with powerful processors that support complex signature matching and can intelligently distinguish between legitimate traffic and potential threats.

In addition to performance, both models are designed with scalability in mind. They can be easily integrated into existing Cisco infrastructures. This facilitates a seamless enhancement of security without causing significant interruptions to ongoing operations. Moreover, they offer flexible deployment options, allowing organizations to operate them inline or out of band depending on their specific needs.

The Cisco IPS4510K9 and IPS4520K9 leverage advanced detection technologies, utilizing a variety of signature types and heuristic analysis to detect known and unknown threats effectively. They are equipped with real-time alerting and reporting capabilities, giving security teams immediate visibility into potential breaches and enabling them to respond swiftly.

Furthermore, both models support a range of management options through the Cisco Security Manager, allowing for centralized administration, streamlined policy management, and enhanced monitoring capabilities. Automated updates ensure the systems remain current with the latest threat intelligence, vital for staying ahead of evolving cyber threats.

In summary, the Cisco Systems IPS4510K9 and IPS4520K9 represent powerful solutions for organizations seeking robust intrusion prevention capabilities. With their high performance, scalability, and advanced detection technologies, these systems are essential tools in the ever-changing landscape of cybersecurity, providing enterprises with the peace of mind needed to operate securely in today's digital world.