Network Layer Attack Interview Questions and Answers for Ethical Hacking

Introduction

Network layer attacks are vital in cybersecurity to safeguard data from unauthorized access or breaches. Attackers exploit vulnerabilities through phishing, malware, or brute force attacks to breach networks. Understanding these threats is crucial for your cybersecurity interview, and our most-asked network layer attack interview questions and answers will help you implement adequate security measures such as firewalls, encryption, and regular audits to protect against unauthorized access and data breaches, ensuring that you are well prepared for your cybersecurity interview. Read these questions about Network security!

Basic Network Layer Attack Questions And Answers

Q1: What Is Network Enumeration?

A: Network Enumeration involves the identification of hosts and devices within a network which employs protocols like ICMP and SNMP to gather information and may scan remote hosts for known services to determine their roles within the network.

Q2: What Is Network Scanning And Enumeration?

A: Network scanning involves probing the network infrastructure to identify live hosts, open ports, and accessible services. Enumeration gathers detailed information about target systems, including user accounts, network configurations, and application-specific data.

Q3: Give An Overview Of Ethical Hacking

A: Ethical hacking, penetration testing, or intrusion testing is a systematic approach to accessing applications, computer systems, networks, or other computing resources with explicit permission from their owners. The goal is identifying and addressing potential threats and vulnerabilities that malicious hackers could exploit.

Its main objective is to strengthen the security of the system or network by identifying and fixing vulnerabilities discovered during testing. Ethical hackers use similar tools and techniques as malicious hackers, but with authorization from authorized entities, to enhance security measures and protect the system from cyber intrusions

Q4: Explain Different Types Of Hacking

A: Hacking encompasses various typologies contingent upon the targeted domain:

• Website Hacking: Unauthorized infiltration into web servers and associated software infrastructures, often intending to tamper information.

• Network Hacking: It is the acquisition of data pertaining to network architecture utilizing tools such as Telnet and ping, often with the aim of disrupting network operations.

• Email Hacking: Unauthorized access to email accounts for illicit purposes.

• Password Hacking: Extraction of confidential passwords from stored data repositories.

Computer Hacking: Illicit access to computer systems for data exfiltration, including sensitive credentials such as passwords and user IDs.

Q5. Explain Trojans And Their Variants

A: A Trojan is crafted by cyber adversaries to infiltrate specific systems. Users are enticed by attractive social media advertisements, leading them to malicious online platforms where Trojans are stealthily activated on their systems.

There are several types of Trojans:

• Trojan-Downloader: Facilitates the download and installation of additional malware payloads.

• Ransomware: Encrypts data stored on computers or devices, often demanding ransom payments for decryption.

• Trojan-Droppers: Complex programs cybercriminals use to install malware, evading detection by conventional antivirus solutions clandestinely.

• Trojan-Rootkits: Conceals the presence of malware and its associated malicious activities on targeted systems.

• Trojan-Banker: Specializes in stealing sensitive user account information related to online banking transactions.

• Trojan-Backdoor: Establishes covert access points, enabling remote entry to compromised systems via remote administration tools (RATs).

Q6: Explain Sniffing And Its Modalities

A: Sniffing involves the surveillance and interception of data packets as they travel through a network. This technique is frequently used by system and network administrators as a diagnostic tool for monitoring network traffic and detecting any irregularities. Sniffing methods include:

• Active Sniffing: This technique entails intercepting and potentially modifying network traffic. It is commonly used in switch-based networks by injecting address resolution packets to monitor traffic between specific targets.

• Passive Sniffing: Network traffic is observed without altering its content in passive sniffing. This method is typically implemented in hub-based network architectures, where traffic is distributed to all network nodes for observation

Q7: What Are Some Different Password Cracking Techniques?

A: Hackers employ various password-cracking techniques to breach security measures. The prominent methods include:

• Dictionary Attack: Hackers utilize a file containing common words and short passwords, often found in dictionaries, to attempt login combinations against user accounts repeatedly.
• Brute-force attacks: Like dictionary attacks, hackers employ this method to try all possible alphanumeric combinations, from aaa1 to zzz10, to crack passwords.
• Man-in-the-Middle Attack: In this technique, attackers intercept and manipulate information exchanged between users and applications or websites, often stealing sensitive data such as social security numbers and account credentials.
• Traffic Interception: Hackers employ packet sniffers to monitor network traffic and capture passwords and other confidential information being transmitted.
• Keylogger Attack: Hackers install software to clandestinely record users' keystrokes, enabling them to gather account credentials and track which websites or applications users access with those credentials.

Advanced Network Layer Attack Questions And Answers

Q8: What Is A Strategic Approach For Red Teamers To Effectively Perform Password Attacks On Various Company Services?

A: Red Teamers use a strategic approach to password attacks, targeting servers and services that authenticate against the victim's LDAP/Active Directory (AD) infrastructure. As companies expand their technological reach, more attack opportunities arise, significantly as they extend their presence online. 

Red Teamers prioritize attacking applications such as email services (e.g., Office 365, OWA), communication tools (e.g., Lync, XMPP, WebEx), collaboration platforms (e.g., JIRA, Slack, Hipchat, Huddle), and external services (e.g., Jenkins, CMS sites, Support sites). By using techniques like Password Spraying, Red Teamers aim to uncover standard credentials to exploit in subsequent attacks, mirroring real-world APT-style campaigns.

Q9: How Can CrackMapExec (CME) Be Utilized To Scan A Network And Potentially Gain Access Using Acquired Credentials?

A: CrackMapExec (CME) proves invaluable in network reconnaissance when armed with acquired credentials from sources like Responder, misconfigured web apps, or brute force attacks. Using CME, one can sweep the network to identify potential entry points. Historically, CME has facilitated network scanning, authentication via SMB, remote command execution across multiple hosts, and even extraction of clear-text credentials using Mimikatz.

With newer features integrating Empire's REST API, users can enhance their capabilities further. Individuals can automatically deploy Empire payloads upon successful authentication by setting up Empire's REST API server, configuring passwords, and connecting CME to Empire. This streamlined process can yield a plethora of Empire shells, particularly potent when utilizing privileged accounts or helpdesk credentials.

Q10: How Can One Extract Passwords From The Windows Credential Store And Web Browsers?

A: The Windows Credential Store, a default feature of Windows, stores usernames, passwords, and certificates for various systems and websites. When users authenticate into a website using Microsoft IE/Edge, their credentials are often prompted to be saved, and this information is stored in the Credential Store. 

There are two types of credentials within the Credential Manager: Web and Windows. Importantly, access to this data is tied to the logged-in user, not the system itself. This accessibility makes it advantageous for attackers, as they typically operate within the user's rights post-phishing or code execution attempts. Interestingly, attackers don't require local administrator privileges to retrieve this data, enhancing the exploit's accessibility.

Q11: How Can One Obtain Local Credentials And Information From MacOS Systems?

A: While much of the lateral movement in cyberattacks often targets Windows environments due to their prevalence of Active Directory, macOS systems are increasingly encountered and must be noticed. 

Once inside a network, attack strategies for macOS resemble those in the Windows realm, including scanning for default credentials, exploiting vulnerabilities in applications like Jenkins, and lateral movement via SSH or VNC. Empire, a versatile tool, offers payloads tailored for macOS, allowing attackers to deploy various agents through ducky scripts, applications, Office macros, Safari launchers, and pkgs, expanding the scope of potential attacks.

Q12: What Is The Significance Of Service Principal Names (SPNs) In Windows Environments, Especially From An Attacker's Perspective?

A: Service Principal Names (SPNs) in Windows facilitate the unique identification of service instances, which is crucial for Kerberos authentication. They link a service instance to a service logon account, covering various services like MSSQL servers, HTTP servers, and print servers. 

For attackers, querying SPNs during enumeration is pivotal as it allows the discovery of service accounts and servers associated with Active Directory without needing to scan individual hosts. Attackers leverage tools like setspn.exe, a default Windows binary, to query Active Directory from any domain-joined computer. With switches like -T, -F, and -Q, attackers can execute comprehensive SPN queries at the domain or forest level, aiding in reconnaissance and potential exploitation.

Q13: How Does Bloodhound Work, And What Does It Mean For Network Visibility And Stealthiness?

A: Bloodhound operates by deploying an Ingestor on a victim system, which then interacts with Active Directory (AD) to collect data on users, groups, and hosts, similar to manual queries. Afterward, the Ingestor attempts connections to each system to identify logged-in users, sessions, and permissions, resulting in noticeable network activity. 

Bloodhound can query every host system in under 10 minutes in larger organizations using Sharphound, potentially raising alarms. However, Bloodhound offers a Stealth option, which exclusively queries AD to reduce network visibility, albeit with limited output. Achieving a balance between thoroughness and stealthiness is essential when using Bloodhound for reconnaissance.

Q14: What Are Some Options In Empire For Lateral Movement Within A Network, And How Do They Work?

A: Empire provides several options for lateral movement within a network:

• inveigh_relay: Relays HTTP/Proxy NTLMv1/NTLMv2 authentication requests to an SMB target, enabling the execution of specified commands or Empire launchers.

• invoke_executemsbuild: Executes a PowerShell command on a local or remote host using MSBuild, bypassing PowerShell.exe.

• invoke_psremoting: Executes a stager on remote hosts using PSRemoting if PSRemoting is enabled.

• invoke_sqloscmd: Executes a command or stager on remote hosts using xp_cmdshell.

• invoke_wmi: Executes a stager on remote hosts using WMI, a reliable method for executing PowerShell payloads.

• jenkins_script_console: This command deploys an Empire agent to a Windows Jenkins server with unauthenticated access to the script console, enabling full RCE.

• invoke_dcom: Invokes commands on remote hosts via MMC20.The application COM object is over DCOM, allowing pivoting.

• invoke_psexec: Executes a stager on remote hosts using PsExec, a traditional method for executing files remotely.

• invoke_smbexec: Executes a stager on remote hosts using SMBExec.ps, similar to PsExec using samba tools.

• invoke_sshcommand: Executes a command on a remote host via SSH.

• invoke_wmi_debugger: This function uses WMI to set the debugger for a target binary on a remote machine, enabling agent execution.

• new_gpo_immediate_task: This function builds an 'Immediate' scheduled task to push out through a specified GPO, allowing for code execution on systems where the GPO is applied.

Q15: What Is Pass-The-Hash (PTH), And Why Is It Significant In Cybersecurity?

A: Pass-the-Hash (PTH) is a method of authentication that uses Windows NTLM hashes instead of user credentials to access systems. NTLM hashes can be easily recovered using tools like Mimikatz, enabling attackers to authenticate without clear-text passwords. PTH attacks can extract hashes for local accounts with local admin access or from the domain controller, posing a threat to security. While newer security measures like the Local Administrator Password Solution (LAPS) mitigate some risks, PTH remains a significant concern if certain conditions are met.

Q16: What Is The Kerberoast Attack, And How Does It Work?

A: The Kerberoast attack exploits a vulnerability in Kerberos authentication, allowing attackers to request Kerberos service tickets for any Service Principal Name (SPN) associated with a target service account. When a service ticket is requested from the Domain Controller, it's encrypted with the associated service user's NTLM hash. Users can request any ticket, so if attackers guess the password corresponding to the NTLM hash, they gain access to the service account's password, compromising security.

Conclusion

JanBask Training's cybersecurity courses provide individuals with the skills to understand and counter threats from attackers exploiting vulnerabilities like weak passwords or misconfigured devices. Whether you're looking to protect network layer attack or prepare for a cybersecurity interview, JanBask training's courses cover effectively implementing robust security measures like firewalls and encryption. Gain expertise in preventing data breaches and financial losses with JanBask training.