Get Eccouncil 312-50 Exam Dumps

Answer : B

The location: operator is the least useful in providing the attacker with sensitive VPN-related information, because it does not directly relate to VPN configuration, credentials, or vulnerabilities. The location: operator finds information for a specific location, such as a city, country, or region. For example, location:paris would return results related to Paris, France. However, this operator does not help the attacker to identify or access VPN servers or clients, unless they are specifically named or indexed by their location, which is unlikely.

The other operators are more useful in providing the attacker with sensitive VPN-related information, because they can help the attacker to find pages or files that contain VPN configuration, credentials, or vulnerabilities. The intitle: operator restricts results to only the pages containing the specified term in the title. For example, intitle:vpn would return pages with VPN in their title, which may include VPN guides, manuals, or tutorials. The inurl: operator restricts the results to only the pages containing the specified word in the URL. For example, inurl:vpn would return pages with VPN in their URL, which may include VPN login portals, configuration files, or directories. The link: operator searches websites or pages that contain links to the specified website or page. For example, link:vpn.com would return pages that link to vpn.com, which may include VPN reviews, comparisons, or recommendations.Reference:

Google Search Operators: The Complete List (44 Advanced Operators)

Footprinting through search engines

Module 02: Footprinting and Reconnaissance

Answer : D

A thin Whois model is a type of data model that is used by some domain registrars for storing and looking up Whois information. In a thin Whois model, the registrar only stores the basic information about the domain, such as the domain name, the registrar name, the name servers, and the registration and expiration dates. The rest of the information, such as the contact details of the domain owner, the administrative contact, and the technical contact, is stored by the registry that manages the top-level domain (TLD) of the domain. For example, the registry for .com and .net domains is Verisign, and the registry for .org domains is Public Interest Registry.When a Whois lookup is performed on a domain that uses a thin Whois model, the registrar's Whois server only returns the basic information and refers the query to the registry's Whois server for the complete information1.

As a hacker, if you are unable to gather complete Whois information from the registrar for a particular set of data, it might be because the domain's registrar is using a thin Whois model and the registry's Whois server is not responding or providing the information. This could be due to various reasons, such as network issues, server errors, rate limits, privacy policies, or legal restrictions. Therefore, the probable data model being utilized by the domain's registrar for storing and looking up Whois information is a thin Whois model working correctly.

Differences Between Thin WHOIS vs Thick WHOIS -- OpenSRS Help & Support

Answer : D

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.Reference:

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

Answer : D

One of the most important actions to secure a web server from common threats is to regularly update and patch the server software. This includes the operating system, the web server software, the database software, and any other applications or frameworks that run on the server. Updating and patching the server software can fix known vulnerabilities, bugs, or errors that could be exploited by attackers to compromise the server or the website. Failing to update and patch the server software can expose the server to common attacks, such as SQL injection, cross-site scripting, remote code execution, denial-of-service, etc.

Installing a web application firewall, limiting the number of concurrent connections to the server, and encrypting the company's website with SSL/TLS are also good practices to secure a web server, but they are not as critical as updating and patching the server software. A web application firewall can filter and block malicious requests, but it cannot prevent attacks that exploit unpatched vulnerabilities in the server software. Limiting the number of concurrent connections to the server can prevent overload and improve performance, but it cannot stop attackers from sending malicious requests or payloads. Encrypting the company's website with SSL/TLS can protect the data in transit between the server and the client, but it cannot protect the data at rest on the server or prevent attacks that target the server itself.

Therefore, the priority action to secure a web server from common threats is to regularly update and patch the server software.

Web Server Security- Beginner's Guide - Astra Security Blog

Top 10 Web Server Security Best Practices | Liquid Web

21 Server Security Tips & Best Practices To Secure Your Server - phoenixNAP

Answer : D

A Denial of Service (DoS) attack is a type of cyberattack that aims to make a machine or network resource unavailable to its intended users by flooding it with traffic or requests that consume its resources. A TCP SYN flood attack is a type of DoS attack that exploits the TCP handshake process by sending a large number of SYN requests to the target server, without completing the connection. A UDP flood attack is a type of DoS attack that sends a large number of UDP packets to random ports on the target server, forcing it to check for the application listening at that port and reply with an ICMP packet. An ICMP flood attack is a type of DoS attack that sends a large number of ICMP packets, such as ping requests, to the target server, overwhelming its ICMP processing capacity.

The attacker's strategy involves a unique mixture of TCP SYN, UDP, and ICMP floods, using 'r' packets per second. The server can handle 'h' packets per second before it starts showing signs of strain. If 'r' surpasses 'h', it overwhelms the server, causing it to become unresponsive. The attacker selects 'r' as a composite number and 'h' as a prime number, making the attack detection more challenging. This is because prime numbers are less predictable and more difficult to factorize than composite numbers, which may hinder the analysis of the attack pattern.

Considering 'r=2010' and different values for 'h', the scenario that would potentially cause the server to falter is the one where 'h=1987' (prime). This is because 'r' is greater than 'h' by 23 packets per second, which means the server cannot handle the incoming traffic and will eventually run out of resources. The other scenarios would not cause the server to falter, as 'h' is either greater than or very close to 'r', which means the server can either manage or barely cope with the incoming traffic.Reference:

What is a denial-of-service (DoS) attack? | Cloudflare

Denial-of-Service (DoS) Attack: Examples and Common Targets - Investopedia

DDoS Attack Types: Glossary of Terms

What is a Denial of Service (DoS) Attack? | Webopedia