Cross-Site Scripting (XSS) attack is the type of cyber attack that involves injecting malicious code into a website and targets the visitor's browser to steal information. Let's understand this in detail:

1. Introduction to Cross-Site Scripting (XSS) attack:
- Cross-Site Scripting (XSS) is a vulnerability that allows attackers to inject malicious scripts into web pages viewed by users.
- The attacker exploits the trust that a user has for a particular website, allowing them to execute malicious code within the user's browser.

2. How XSS attack works:
- The attacker identifies a vulnerable website that does not properly validate or sanitize user inputs.
- They inject malicious code, usually in the form of JavaScript, into the website's input fields, comments, or other user-controlled areas.
- When a visitor accesses the infected page, the malicious code is executed in their browser.
- The browser treats the injected code as legitimate and allows it to run, giving the attacker access to sensitive information such as login credentials, session cookies, or personal data.

3. Types of XSS attacks:
- Stored XSS: The malicious code is permanently stored on the targeted website, and every user who visits the infected page is affected.
- Reflected XSS: The malicious code is embedded in a URL or other user input and is only triggered when the victim clicks on a crafted link or visits a specific page.
- DOM-based XSS: The attack occurs entirely within the victim's browser, manipulating the Document Object Model (DOM) to execute malicious code.

4. Impact and consequences of XSS attacks:
- Theft of sensitive information: Attackers can steal login credentials, personal data, or financial information entered by users on the infected website.
- Session hijacking: XSS attacks can allow attackers to hijack user sessions, impersonating legitimate users and gaining unauthorized access to their accounts.
- Malware distribution: Attackers can use XSS vulnerabilities to distribute malware, infecting visitors' browsers and compromising their systems.
- Reputation damage: Websites that are vulnerable to XSS attacks may suffer reputational damage, leading to loss of user trust and potential legal consequences.

In conclusion, Cross-Site Scripting (XSS) attacks involve injecting malicious code into a website to target visitors' browsers, enabling the theft of sensitive information. It is crucial for website developers to implement proper input validation and sanitization techniques to mitigate the risk of XSS vulnerabilities.