GAQM CPEH-001 Exam Questions

Firewalking uses a traceroute-like IP packet analysis to determine whether or not a particular packet can pass from the attacker's host to a destination host through a packet-filtering device. This technique can be used to map 'open' or 'pass through' ports on a gateway. More over, it can determine whether packets with various control information can pass through a given gateway.

Canaries or canary words are known values that are placed between a buffer and control data on the stack to monitor buffer overflows. When the buffer overflows, it will clobber the canary, making the overflow evident. This is a reference to the historic practice of using canaries in coal mines, since they would be affected by toxic gases earlier than the miners, thus providing a biological warning system.

When a Nic is set to Promiscuous mode it just blindly takes whatever comes through to it network interface and sends it to the Application layer. This is why they are so hard to detect. Actually you could use ARP requests and Send them to every pc and the one which responds to all the requests can be identified as a NIC on Promiscuous mode and there are some very special programs that can do this for you. But considering the alternatives in the question the right answer has to be that the interface cannot be detected.

fragroute intercepts, modifies, and rewrites egress traffic destined for a specified host, implementing most of the attacks described in the Secure Networks 'Insertion, Evasion, and Denial of Service: Eluding Network Intrusion Detection' paper of January 1998. It features a simple ruleset language to delay, duplicate, drop, fragment, overlap, print, reorder, segment, source-route, or otherwise monkey with all outbound packets destined for a target host, with minimal support for randomized or probabilistic behaviour. This tool was written in good faith to aid in the testing of network intrusion detection systems, firewalls, and basic TCP/IP stack behaviour.

Because of the complexity of the underlying problems, most public-key algorithms involve operations such as modular multiplication and exponentiation, which are much more computationally expensive than the techniques used in most block ciphers, especially with typical key sizes. As a result, public-key cryptosystems are commonly 'hybrid' systems, in which a fast symmetric-key encryption algorithm is used for the message itself, while the relevant symmetric key is sent with the message, but encrypted using a public-key algorithm. Similarly, hybrid signature schemes are often used, in which a cryptographic hash function is computed, and only the resulting hash is digitally signed.