Clive is conducting a pen-test and has just port scanned a system on the network. He has identified the operating system as Linux and been able to elicit responses from ports 23, 25 and 53. He infers port 23 as running Telnet service, port 25 as running SMTP service and port 53 as running DNS service. The client confirms these findings and attests to the current availability of the services. When he tries to telnet to port 23 or 25, he gets a blank screen in response. On typing other commands, he sees only blank spaces or underscores symbols on the screen. What are you most likely to infer from this?

Bob has a good understanding of cryptography, having worked with it for many years. Cryptography is used to secure data from specific threats, but it does not secure the application from coding errors. It can provide data privacy; integrity and enable strong authentication but it cannot mitigate programming errors. What is a good example of a programming error that Bob can use to explain to the management how encryption will not address all their security concerns?

Jess the hacker runs L0phtCrack's built-in sniffer utility that grabs SMB password hashes and stores them for offline cracking. Once cracked, these passwords can provide easy access to whatever network resources the user account has access to. But Jess is not picking up hashes from the network. Why?

Simon is security analyst writing signatures for a Snort node he placed internally that captures all mirrored traffic from his border firewall. From the following signature, what will Snort look for in the payload of the suspected packets?
alert tcp $EXTERNAL_NET any -> $HOME_NET 27374 (msG. "BACKDOOR SIG -SubSseven 22";flags: A+; content: "|0d0a5b52504c5d3030320d0a|"; reference:arachnids, 485;) alert

What is the proper response for a NULL scan if the port is closed?