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- The original author of this article: Brother Gu’s younger brother
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Hackers and white hats
Some children's shoes think that hackers and white hats are the same thing, but they are not; moreover, their working methods and goals are also very different.
Hackers refer to a group of people who specialize in using computer technology to attack, intrude, crack and steal information. Hackers are sometimes divided into "good hackers" (white hats) and "bad hackers" (hackers). The former usually engage in activities in the security field and assist in maintaining the security of systems and networks; the latter use technical means to obtain illegal benefits or Undermining Internet security. Hackers can attack computer systems in various ways, such as exploiting vulnerabilities to attack, brute force cracking passwords, and obtaining user account information through social engineering methods. The targets of hacking attacks are wide-ranging, which can be government agencies, banks, hospitals, companies, personal computers, etc. The losses caused by hacker attacks are not only economical, but may also cause personal privacy leakage or national security issues.
White Hat (White Hat) refers to a person who specializes in network and computer technology defense. They mainly detect and repair security vulnerabilities in the system. White hats can identify security vulnerabilities in computer systems or network systems, but usually do not exploit these vulnerabilities maliciously, but submit the discovered vulnerabilities to the corresponding SRC (Security Response Center) or software vendors to help them patch the vulnerabilities and improve System security. White hats are usually employed by major companies as network security engineers and security consultants. Different from black hats (also known as hackers), white hats focus on protecting network security, actively complying with laws and regulations, and conducting technical research and security testing within the legal scope.
Overview of the main means of website attack
It is the main means of several common website attacks:
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SQL injection attack: Attackers can obtain sensitive information in the database by entering malicious code in URLs or forms, and even control the entire website.
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XSS attack: Attackers inject malicious scripts into websites to steal sensitive information of users or bypass access restrictions.
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CSRF attack: take advantage of the user's trust in certain websites, and forge requests to complete some illegal operations without the user's knowledge, such as submitting a form or sending an email.
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DDos attack: The attacker uses a large number of computers or network devices to send requests to the target website, exhausting its bandwidth and system resources, causing it to stop services or fail to work normally.
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File upload vulnerability: Attackers gain control of the website server by uploading malicious files, such as Trojan horses or viruses.
The above are just some common website attack methods. Different attackers use different techniques to attack. Therefore, website security requires multi-layer defense measures, including but not limited to Web Application Firewall, verification code, HTTPS protocol encryption, and input filtering.
SQL injection attack
SQL injection attack refers to an attack method in which attackers inject malicious SQL statements into web applications to perform unauthorized database queries, obtain sensitive data, or implement unauthorized operations. Many web applications use background databases to store and retrieve data, and display them differently among different users according to different needs. However, due to some improper coding or security settings, the attacker can inject the SQL statement constructed by himself into the application through URL parameters, form submission, etc.
Through SQL injection attacks, attackers can bypass the login verification mechanism and enter the system by guessing user names and passwords; they can also steal sensitive information of users, such as credit card numbers, social security numbers, personal passwords, etc.; for website administrators, SQL injection attacks can even Can allow an attacker to gain full control over the database.
To avoid SQL injection attacks, developers need to conduct detailed investigations at all stages of application design, development, and testing, abide by security regulations, and take corresponding security measures. For example, restrict user permissions, filter input, use parameterized queries, turn off error message prompts, etc. At the same time, using a Web Application Firewall (WAF) is also an effective measure to prevent SQL injection attacks.
XSS attack
A Cross-Site Scripting (XSS) attack refers to an attacker injecting malicious scripts or codes into a web application so that it can be executed by other users when browsing the page, thereby achieving the purpose of the attack. This kind of attack usually inserts malicious code constructed by the attacker into the Web page, and then allows the attacked user to browse, causing the malicious code to be executed in the victim's browser.
According to the source, XSS attacks are usually divided into three categories: reflected XSS attacks, stored XSS attacks, and DOM-based XSS attacks. Among them, reflective XSS mainly induces users to click by constructing links containing attack code; stored XSS mainly means that attackers store malicious code on the server, so that all users who visit the page will trigger malicious code; DOM-based XSS It is to use the script code of the client to modify the original data of the browser to make it run malicious code and achieve the purpose of attack.
XSS attacks can steal users' sensitive information, hijack users' sessions, and tamper with website content, etc., bringing great harm to users and websites. To avoid XSS attacks, developers need to conduct detailed investigations at each stage of application design, development, and testing, and adopt protective measures, such as data filtering, encoding output, and setting HTTP headers, to ensure application security and stability.
CSRF attack
A cross-site request forgery (CSRF) attack refers to an attacker who induces the victim to enter a third-party website. In the third-party website, the victim uses the identity of the victim who has logged in to other websites to initiate an attack on other websites that the victim has logged in. A method of attack that performs illegal operations in the victim's account without their knowledge. CSRF attacks can be carried out in various ways, such as emails, pictures, videos, web chats, etc.
The principle of CSRF attack is to use the vulnerabilities or defects of the attacked website, so that the attacker can control the victim to carry specific cookie information during operation, and then use these cookie information to carry out illegal operations. Since the attack utilizes the account information that the user has logged in, it is difficult for the user to detect it.
In order to prevent CSRF attacks, web applications need to distinguish and verify access sources and identities, such as using verification codes and adding token verification mechanisms. At the same time, users also need to pay attention to protecting their account information, such as avoiding leaking passwords to others, not trusting unknown emails, and updating anti-virus software in time.
DDos attack
DDoS (Distributed Denial of Service, distributed denial of service attack) is a network attack method that uses multiple computers or devices to send a large amount of traffic or requests to the target server at the same time, causing network services to be paralyzed or unavailable.
DDoS attacks often take advantage of loopholes in network communication protocols, allowing attackers to forge a large number of request packets or data packets, and send massive data traffic to the victim's server, causing server resources to be exhausted, so that normal users cannot access the victim's server. website or other services.
DDoS attack is very harmful. It can cause the target server to be paralyzed, unable to undertake normal network services, and may even cause serious property losses and reputational impacts. In order to avoid DDoS attacks, website administrators need to take effective measures, such as increasing network bandwidth, using specialized firewalls and security devices, limiting traffic, filtering abnormal traffic, etc., to ensure network security. At the same time, it is also necessary to strengthen the monitoring and response mechanism to detect and deal with threats in time to avoid greater losses.
File Upload Vulnerability
The file upload vulnerability is a security vulnerability. It is due to the lack of control or processing defects in the part of the user's file upload by the programmer, which allows the attacker to upload an executable dynamic script file to the server, thereby obtaining the authority to execute commands on the server. . Attackers can upload files containing malicious codes, such as WebShell, Trojans, etc., which may cause serious consequences after being uploaded. This vulnerability has a high probability of occurrence in business application systems, because the file upload function is very common in business application systems, and if the relevant security checks are ignored in the system design, it will easily lead to file upload vulnerabilities.