2021 Apr 312-50 latest exam

Q311. Which of the following Nmap commands would be used to perform a stack fingerprinting? 

A. Nmap -O -p80 <host(s.> 

B. Nmap -hU -Q<host(s.> 

C. Nmap -sT -p <host(s.> 

D. Nmap -u -o -w2 <host> 

E. Nmap -sS -0p target 

Answer: A

Explanation: This option activates remote host identification via TCP/IP fingerprinting. In other words, it uses a bunch of techniques to detect subtlety in the underlying operating system network stack of the computers you are scanning. It uses this information to create a "fingerprint" which it compares with its database of known OS fingerprints (the nmap-os-fingerprints file. to decide what type of system you are scanning. 


Q312. Justine is the systems administrator for her company, an international shipping company with offices all over the world. Recent US regulations have forced the company to implement stronger and more secure means of communication. Justine and other administrators have been put in charge of securing the company's digital communication lines. After implementing email encryption, Justine now needs to implement robust digital signatures to ensure data authenticity and reliability. Justine has decided to implement digital signatures which are a variant of DSA and that operate on elliptical curve groups. These signatures are more efficient than DSA and are not vulnerable to a number field sieve attacks. 

What type of signature has Justine decided to implement? 

A. She has decided to implement ElGamal signatures since they offer more reliability than the typical DSA signatures 

B. Justine has decided to use ECDSA signatures since they are more efficient than DSA signatures 

C. Justine is now utilizing SHA-1 with RSA signatures to help ensure data reliability 

D. These types of signatures that Justine has decided to use are called RSA-PSS signatures 

Answer: B

Explanation: The Elliptic Curve Digital Signature Algorithm (ECDSA) is a variant of the Digital Signature Algorithm (DSA) which uses Elliptic curve cryptography. http://en.wikipedia.org/wiki/Elliptic_Curve_DSA 


Q313. Jason works in the sales and marketing department for a very large advertising agency located in Atlanta. Jason is working on a very important marketing campaign for his company's largest client. Before the project could be completed and implemented, a competing advertising company comes out with the exact same marketing materials and advertising, thus rendering all the work done for Jason's client unusable. Jason is questioned about this and says he has no idea how all the material ended up in the hands of a competitor. 

Without any proof, Jason's company cannot do anything except move on. After working on another high profile client for about a month, all the marketing and sales material again ends up in the hands of another competitor and is released to the public before Jason's company can finish the project. Once again, Jason says that he had nothing to do with it and does not know how this could have happened. Jason is given leave with pay until they can figure out what is going on. 

Jason's supervisor decides to go through his email and finds a number of emails that were sent to the competitors that ended up with the marketing material. The only items in the emails were attached jpg files, but nothing else. Jason's supervisor opens the picture files, but cannot find anything out of the ordinary with them. 

What technique has Jason most likely used? 

A. Stealth Rootkit Technique 

B. Snow Hiding Technique 

C. ADS Streams Technique 

D. Image Steganography Technique 

Answer: D


Q314. Windows LAN Manager (LM) hashes are known to be weak. Which of the following are known weaknesses of LM? (Choose three) 

A. Converts passwords to uppercase. 

B. Hashes are sent in clear text over the network. 

C. Makes use of only 32 bit encryption. 

D. Effective length is 7 characters. 

Answer: ABD

Explanation: The LM hash is computed as follows.1. The user’s password as an OEM string is converted to uppercase. 2. This password is either null-padded or truncated to 14 bytes. 3. The “fixed-length” password is split into two 7-byte halves. 4. These values are used to create two DES keys, one from each 7-byte half. 5. Each of these keys is used to DES-encrypt the constant ASCII string “KGS!@#$%”, resulting in two 8-byte ciphertext values. 6. These two ciphertext values are concatenated to form a 16-byte value, which is the LM hash. The hashes them self are sent in clear text over the network instead of sending the password in clear text. 


Q315. You have just received an assignment for an assessment at a company site. Company's management is concerned about external threat and wants to take appropriate steps to insure security is in place. Anyway the management is also worried about possible threats coming from inside the site, specifically from employees belonging to different Departments. What kind of assessment will you be performing ? 

A. Black box testing 

B. Black hat testing 

C. Gray box testing 

D. Gray hat testing 

E. White box testing 

F. White hat testing 

Answer: C 

Explanation: Internal Testing is also referred to as Gray-box testing. 


Q316. You are scanning into the target network for the first time. You find very few conventional ports open. When you attempt to perform traditional service identification by connecting to the open ports, it yields either unreliable or no results. You are unsure of what protocols are being used. You need to discover as many different protocols as possible. Which kind of scan would you use to do this? 

A. Nmap with the –sO (Raw IP packets) switch 

B. Nessus scan with TCP based pings 

C. Nmap scan with the –sP (Ping scan) switch 

D. Netcat scan with the –u –e switches 

Answer: A

Explanation: Running Nmap with the –sO switch will do a IP Protocol Scan. The IP protocol scan is a bit different than the other nmap scans. The IP protocol scan is searching for additional IP protocols in use by the remote station, such as ICMP, TCP, and UDP. If a router is scanned, additional IP protocols such as EGP or IGP may be identified. 


Q317. Exhibit 

You receive an e-mail with the message displayed in the exhibit. 

From this e-mail you suspect that this message was sent by some hacker since you have using their e-mail services for the last 2 years and they never sent out an e-mail as this. You also observe the URL in the message and confirm your suspicion about 340590649. You immediately enter the following at the Windows 2000 command prompt. 

ping 340590649 

You get a response with a valid IP address. What is the obstructed IP address in the e-mail URL? 

A. 192.34.5.9 

B. 10.0.3.4 

C. 203.2.4.5 

D. 199.23.43.4 

Answer: C

Explanation: Convert the number in binary, then start from last 8 bits and convert them to decimal to get the last octet (in this case .5) 


Q318. NTP allows you to set the clocks on your systems very accurately, to within 100ms and sometimes-even 10ms. Knowing the exact time is extremely important for enterprise security. Various security protocols depend on an accurate source of time information in order to prevent "playback" attacks. These protocols tag their communications with the current time, to prevent attackers from replaying the same communications, e.g., a login/password interaction or even an entire communication, at a later date. One can circumvent this tagging, if the clock can be set back to the time the communication was recorded. An attacker attempts to try corrupting the clocks on devices on your network. You run Wireshark to detect the NTP traffic to see if there are any irregularities on the network. What port number you should enable in Wireshark display filter to view NTP packets? 

A. TCP Port 124 

B. UDP Port 125 

C. UDP Port 123 

D. TCP Port 126 

Answer: C


Q319. Exhibit: * Missing* 

Jason's Web server was attacked by a trojan virus. He runs protocol analyzer and notices that the trojan communicates to a remote server on the Internet. Shown below is the standard "hexdump" representation of the network packet, before being decoded. Jason wants to identify the trojan by looking at the destination port number and mapping to a trojan-port number database on the Internet. Identify the remote server's port number by decoding the packet? 

A. Port 1890 (Net-Devil Trojan) 

B. Port 1786 (Net-Devil Trojan) 

C. Port 1909 (Net-Devil Trojan) 

D. Port 6667 (Net-Devil Trojan) 

Answer: D

Explanation: From trace, 0x1A0B is 6667, IRC Relay Chat, which is one port used. Other ports are in the 900's. 


Q320. One of the most common and the best way of cracking RSA encryption is to being to derive the two prime numbers, which are used in the RSA PKI mathematical process. If the two numbers p and q are discovered through a _________________ process, then the private key can be derived. 

A. Factorization 

B. Prime Detection 

C. Hashing 

D. Brute-forcing 

Answer: A

Explanation: In April 1994, an international cooperative group of mathematicians and computer scientists solved a 17-year-old challenge problem, the factoring of a 129-digit number, called RSA-129, into two primes. That is, RSA-129 = 1143816257578888676692357799761466120102182 9672124236256256184293570693524573389783059 7123563958705058989075147599290026879543541 = 34905295108476509491478496199038 98133417764638493387843990820577 times 32769132993266709549961988190834 461413177642967992942539798288533. Se more at http://en.wikipedia.org/wiki/RSA_Factoring_Challenge