In CEH v13 Module 17: Mobile and IoT Security, Spearphone is defined as a privacy-intrusion attack that:
Exploits a smartphone's speaker output, particularly when loudspeaker mode is used.
Leverages motion sensors (accelerometer, gyroscope) through a malicious app to capture acoustic signals emitted during:
Phone calls
Voice assistant interactions
Media playback
This enables attackers to extract private speech content without needing microphone access.
Option Clarification:
A: Man-in-the-disk: Exploits unprotected external storage in Android.
B: aLTEr: Exploits LTE protocol weaknesses; unrelated to loudspeaker eavesdropping.
C: SIM card attack: Targets SIM-level vulnerabilities (e.g., SIMjacker).
D: Spearphone: Correct - exploits loudspeaker emissions and motion sensors.
Reference:
Module 17 - Mobile Device Exploits # Spearphone Attack Vector
Research: Spearphone: Exploiting Smart Device Sensors via Loudspeaker Audio

Webhooks are one of a few ways internet applications will communicate with one another.
It allows you to send real-time data from one application to another whenever a given event happens.
For example, let's say you've created an application using the Foursquare API that tracks when people check into your restaurant. You ideally wish to be able to greet customers by name and provide a complimentary drink when they check in.
What a webhook will is notify you any time someone checks in, therefore you'd be able to run any processes that you simply had in your application once this event is triggered.
The data is then sent over the web from the application wherever the event originally occurred, to the receiving application that handles the data.
Here's a visual representation of what that looks like:

A webhook url is provided by the receiving application, and acts as a phone number that the other application will call once an event happens.
Only it's more complicated than a phone number, because data about the event is shipped to the webhook url in either JSON or XML format. this is known as the "payload." Here's an example of what a webhook url looks like with the payload it's carrying:

What are Webhooks? Webhooks are user-defined HTTP callback or push APIs that are raised based on events triggered, such as comment received on a post and pushing code to the registry. A webhook allows an application to update other applications with the latest information. Once invoked, it supplies data to the other applications, which means that users instantly receive real-time information. Webhooks are sometimes called
"Reverse APIs" as they provide what is required for API specification, and the developer should create an API to use a webhook. A webhook is an API concept that is also used to send text messages and notifications to mobile numbers or email addresses from an application when a specific event is triggered. For instance, if you search for something in the online store and the required item is out of stock, you click on the "Notify me" bar to get an alert from the application when that item is available for purchase. These notifications from the applications are usually sent through webhooks.

A Multipartite Virus is designed to infect both the boot sector and executable files of a system. This makes it more complex and harder to remove than viruses that target only one area. It can spread in multiple ways and activate under different conditions depending on whether the infected file or boot sector is accessed first.
CEH v13 Official Curriculum states:
"Multipartite viruses infect both the boot sector and program files. They are difficult to remove and can reinfect the system unless both locations are cleaned simultaneously." Incorrect Options:
* A. Polymorphic viruses change their code signatures but do not necessarily target both boot and executable areas.
* B. Stealth viruses conceal their presence, often by intercepting system calls.
* D. Macro viruses infect macro-enabled files, typically in Microsoft Office documents.
Reference - CEH v13 Guide:
Module 06: Malware Threats
Topic: Types of Malware - Multipartite Viruses

The hosts file on a computer maps domain names to IP addresses locally. By modifying this file, an attacker can redirect traffic destined for legitimate sites (e.g., www.MyPersonalBank.com) to malicious IP addresses (e.g., a phishing server).
The hosts file takes precedence over DNS queries, making it a simple but powerful tool for local redirection.
Windows hosts file location: C:\Windows\System32\drivers\etc\hosts
Linux/Unix hosts file location: /etc/hosts
Reference - CEH v13 Official Study Guide:
Module 6: Malware Threats
Quote:
"Attackers can redirect users to phishing or malware sites by altering the local hosts file, bypassing DNS resolution." Incorrect Options:
A: boot.ini is for boot configuration, not DNS resolution.
B: sudoers controls administrative privileges in Linux.
C: networks is for defining network names, not URL resolution.

Restrict results to those of a certain filetype. E.g., PDF, DOCX, TXT, PPT, etc. Note: The "ext:" operator can also be used-the results are identical.
Example: apple filetype:pdf / apple ext:pdf