ECCouncil Updated 312-50v13 Exam Questions and Answers by ariah

In LM hashing (used in legacy Windows systems), passwords are split into two 7-character chunks. If a password is fewer than 8 characters, the second half is padded with nulls and hashed to a constant value.

That constant is:

AAD3B435B51404EE

Thus, the second half of the LM hash (the rightmost 16 characters) is always the same if the password is < 8 characters.

From CEH v13 Courseware:

Module 6: Malware Threats → LM Hash Characteristics

CEH v13 Study Guide states:

“If the password is less than 8 characters, the second half of the LM hash will always be ‘AAD3B435B51404EE’, indicating the hash belongs to a short password.”

A SYN flood attack is a type of denial-of-service (DoS) attack that exploits the TCP handshake process by sending a large number of SYN requests to the target server, without completing the connection. This consumes the connection state tables on the server, preventing it from accepting new connections. The attacker has crafted an automated botnet to simultaneously send ‘s’ SYN packets per second to the server. The server can handle ‘f’ SYN packets per second without any performance issues. If ‘s’ exceeds ‘f’, the network infrastructure begins to show signs of overload. The system’s response time increases exponentially (24k), where ‘k’ represents each additional SYN packet above the ‘f’ limit.

Considering ‘s=500’ and different ‘f’ values, the scenario that is most likely to cause the server to experience overload and significantly increased response times is the one where ‘f=420’. This is because ‘s’ is greater than ‘f’ by 80 packets per second, which means the server cannot handle the incoming traffic and will eventually run out of resources. The response time shoots up (2480 = 281,474,976,710,656 times the normal response time), indicating a system overload.

The other scenarios are less likely or less severe than the one where ‘f=420’. Option A has ‘f=510’, which is greater than ‘s’, so the system stays stable and the response time remains unaffected. Option B has ‘f=495’, which is less than ‘s’ by 5 packets per second, so the response time drastically rises (245 = 32 times the normal response time), indicating a probable system overload, but not as extreme as option D. Option C has ‘f=505’, which is less than ‘s’ by 5 packets per second, so the response time increases but not as drastically (245 = 32 times the normal response time), and the system might still function, albeit slowly. References:

SYN flood DDoS attack | Cloudflare

SYN flood - Wikipedia

What Is a SYN Flood Attack? | F5

What is a SYN flood attack and how to prevent it? | NETSCOUT

WEP encryption is an outdated and insecure method of protecting wireless networks from unauthorized access and eavesdropping. WEP uses a static key that can be easily cracked by various tools and techniques, such as capturing the initialization vectors, brute-forcing the key, or exploiting the weak key scheduling algorithm1. Therefore, you should recommend a more secure encryption method to enhance the security of the company’s wireless network.

One of the most suitable replacements for WEP encryption is WPA2-PSK with AES encryption. WPA2 stands for Wi-Fi Protected Access 2, which is a security standard that improves upon the previous WPA standard. WPA2 uses a robust encryption algorithm called AES, which stands for Advanced Encryption Standard. AES is a block cipher that uses a 128-bit key and is considered to be very secure and resistant to attacks2.

WPA2-PSK stands for WPA2 Pre-Shared Key, which is a mode of WPA2 that uses a passphrase or a password to generate the encryption key. The passphrase or password must be entered by the users who want to connect to the wireless network. The key is then derived from the passphrase or password using a function called PBKDF2, which stands for Password-Based Key Derivation Function 2. PBKDF2 adds a salt and a number of iterations to the passphrase or password to make it harder to crack3.

WPA2-PSK with AES encryption offers several advantages over WEP encryption, such as:

It uses a dynamic key that changes with each session, instead of a static key that remains the same.

It uses a stronger encryption algorithm that is more difficult to break, instead of a weaker encryption algorithm that is more vulnerable to attacks.

It uses a longer key that provides more security, instead of a shorter key that provides less security.

It uses a more secure key derivation function that adds complexity and randomness, instead of a simple key generation function that is predictable and flawed.

Therefore, you should recommend WPA2-PSK with AES encryption as a suitable replacement to enhance the security of the company’s wireless network.

aLTEr attacks are usually performed on LTE devices Attacker installs a virtual (fake) communication tower between two authentic endpoints intending to mislead the victim This virtual tower is used to interrupt the data transmission between the user and real tower attempting to hijack the active session.

https://alter-attack.net/media/breaking_lte_on_layer_two.pdf

The new aLTEr attack can be used against nearly all LTE connected endpoints by intercepting traffic and redirecting it to malicious websites together with a particular approach for Apple iOS devices.

This attack works by taking advantage of a style flaw among the LTE network — the information link layer (aka: layer-2) of the LTE network is encrypted with AES-CTR however it’s not integrity-protected, that is why an offender will modify the payload.

As a result, the offender is acting a classic man-in-the-middle wherever they’re movement as a cell tower to the victim.