Imagine opening a seemingly ordinary email, and the next moment, your bank account is empty. Or you're browsing the web when your screen locks and a ransom message pops up. These scenes are not science fiction movies, but real-life examples of cyberattacks. In this era of the Internet of everything, the Internet is not only a convenient bridge, but also a hunting ground for hackers. From personal privacy to corporate secrets to national security, cyber Attacks are everywhere, and their cunning and destructive power is chilling. What attacks are threatening us? How do they work, and what should be done about it? Let's take a look at eight of the most common cyberattacks, taking you into a world both familiar and unfamiliar.
Malware
1. What is Malware? Malware is a malicious program designed to damage, steal, or control a user's system. It sneaking into user devices through seemingly innocuous routes such as email attachments, disguised software updates, or illegal website downloads. Once running, malware can steal sensitive information, encrypt data, delete files, or even turn the device into an attacker's "puppet".
2. Common types of malware
Virus: Attached to legitimate programs, after running, self-replication, infection of other files, resulting in system performance degradation or data loss.
Worm: It can propagate independently without host program. It is common to self-spread through network vulnerabilities and consume network resources. Trojan: Masquerading as legitimate software to induce users to install a backdoor that can remotely control devices or steal data.
Spyware: Secretly monitoring user behavior, recording keystrokes or browsing history, often used to steal passwords and bank account information.
Ransomware: locking a device or encrypted data for ransom to unlock it has been particularly rampant in recent years.
3. Propagation and Harm Malware is usually spread through physical media such as phishing emails, Malvertising, or USB keys. The harm can include data leakage, system failure, financial loss, and even the loss of corporate reputation. For example, the 2020 Emotet malware became an enterprise security nightmare by infecting millions of devices worldwide through disguised Office documents.
4. Prevention strategies
• Install and regularly update anti-virus software to scan for suspicious files.
• Avoid clicking on unknown links or downloading software from unknown sources.
• Back up important data regularly to prevent irreversible losses caused by ransomware.
• Enable firewalls to restrict unauthorized network access.
Ransomware
1. How Ransomware works Ransomware is a special type of malware that specifically locks down a user's device or encrypts critical data (e.g., documents, databases, source code) so that the victim cannot access it. Attackers typically demand payment in hard-to-track cryptocurrencies such as bitcoin, and threaten to permanently destroy the data if the payment is not made.
2. Typical Cases
The Colonial Pipeline attack in 2021 shocked the world. The DarkSide ransomware encrypted the control system of the major fuel pipeline on the East Coast of the United States, causing the fuel supply to be interrupted and the attackers demanding a ransom of $4.4 million. This incident exposed the vulnerability of critical infrastructure to ransomware.
3. Why is ransomware so deadly?
High concealment: Ransomware is often spread through social engineering (e.g., masquerading as legitimate emails), making it difficult for users to detect.
Rapid diffusion: By exploiting network vulnerabilities, ransomware can quickly infect multiple devices within an enterprise.
Difficult recovery: Without a valid backup, paying the ransom may be the only option, but it may not be possible to recover the data after paying the ransom.
4. Defensive Measures
• Regularly backup data offline to ensure that critical data can be quickly restored.
• Endpoint Detection and Response (EDR) system was deployed to monitor abnormal behavior in real time.
• Train employees to identify phishing emails so they don't become attack vectors.
• Patch system and software vulnerabilities in time to reduce the risk of intrusion.
Phishing
1. The Nature of Phishing
Phishing is a type of social engineering attack in which an attacker, posing as a trusted entity (such as a bank, e-commerce platform, or a colleague), induces a victim to disclose sensitive information (such as passwords, credit card numbers) or click on a malicious link via email, text message, or instant message.
2. Common Forms
• Email phishing: Fake official emails to entice users to log in to fake websites and enter their credentials.
Spear Phishing: A tailored attack aimed at a specific individual or group with a higher success rate.
• Smishing: Sending fake notifications via text messages to entice users to click on malicious links.
• Vishing: pretending to be an authority over the phone to obtain sensitive information.
3. Hazards and Effects
Phishing attacks are cheap and easy to implement, but they can cause huge losses. In 2022, global financial losses due to phishing attacks amounted to billions of dollars, involving stolen personal accounts, corporate data breaches, and more.
4. Coping Strategies
• Double-check the sender address for typos or unusual domain names.
• Enable multi-factor authentication (MFA) to reduce risk even if passwords are compromised.
• Use anti-phishing tools to filter out malicious emails and links.
• Conduct regular security awareness training to enhance staff vigilance.
Advanced Persistent Threat (APT)
1. Definition of APT
An advanced persistent threat (APT) is a complex, long-term cyber attack, usually carried out by state-level hacker groups or criminal gangs. APT attack has a clear target and a high degree of customization. Attackers infiltrate through multiple stages and lurk for a long time to steal confidential data or damage the system.
2. Attack Flow
Initial intrusion: Gaining entry through phishing emails, exploits, or supply chain attacks.
Establish a foothold: Insert backdoors to maintain long-term access.
Lateral Movement: spread within the target network to obtain higher authority.
Data Theft: Extracting sensitive information such as intellectual property or strategy documents.
Cover the Trace: Delete the log to hide the attack.
3. Typical Cases
The SolarWinds attack in 2020 was a classic APT incident in which hackers planted malicious code through a supply chain attack, affecting thousands of businesses and government agencies around the world and stealing large amounts of sensitive data.
4. Defensive Points
• Deploy an Intrusion detection system (IDS) to monitor abnormal network traffic.
• Enforce the principle of least privilege to limit lateral movement of attackers.
• Conduct regular security audits to detect potential backdoors.
• Work with threat intelligence platforms to capture the latest attack trends.
Man in the Middle Attack (MITM)
1. How Man-in-the-middle attacks work?
A man-in-the-middle attack (MITM) is when an attacker inserts, intercepts, and manipulates data transmissions between two communicating parties without them knowing about it. An attacker may steal sensitive information, tamper with data, or impersonate a party for fraud.
2. Common Forms
• Wi-Fi spoofing: Attackers create fake Wi-Fi hotspots to induce users to connect in order to steal data.
DNS spoofing: tampering with DNS queries to direct users to malicious websites.
• SSL hijacking: Forging SSL certificates to intercept encrypted traffic.
• Email hijacking: Intercepting and tampering with email content.
3. Hazards
MITM attacks pose a significant threat to online banking, e-commerce, and telecommuting systems, which can lead to stolen accounts, tampered transactions, or exposure of sensitive communications.
4. Preventive Measures
• Use HTTPS websites to ensure communication is encrypted.
• Avoid connecting to public Wi-Fi or using VPNS to encrypt traffic.
• Enable a secure DNS resolution service such as DNSSEC.
• Check the validity of SSL certificates and be alert for exception warnings.
SQL Injection
1. Mechanism of SQL Injection
SQL injection is a code injection attack in which an attacker inserts malicious SQL statements into the input fields of a Web application (e.g., login box, search bar) to trick the database into executing illegal commands, thereby stealing, tampering or deleting data.
2. Attack Principle
Consider the following SQL query for a login form:
The attacker enters:
The query becomes:
This bypasses authentication and allows the attacker to log in.
3. Hazards
SQL injection can lead to leakage of database contents, theft of user credentials, or even entire systems being taken over. The Equifax data breach in 2017 was linked to an SQL injection vulnerability that affected the personal information of 147 million users.
4. Defenses
• Use parameterized queries or precompiled statements to avoid directly concatenating user input.
• Implement input validation and filtering to reject anomalous characters.
• Restrict database permissions to prevent attackers from performing dangerous actions.
• Regularly scan Web applications for vulnerabilities and patch security risks.
DDoS Attacks
1. Nature of DDoS Attacks
Distributed Denial of Service (DDoS) attack sends massive requests to the target server by controlling a large number of bots, which exhausts its bandwidth, session resources or computing power, and makes normal users unable to access the service.
2. Common Types
• Traffic attack: sending a large number of packets and blocking the network bandwidth.
• Protocol attacks: Exploit TCP/IP protocol vulnerabilities to exhaust server session resources.
• Application-layer attacks: Paralyze Web servers by impersonating legitimate user requests.
3. Typical Cases
The Dyn DDoS attack in 2016 used Mirai botnet to bring down several mainstream websites including Twitter and Netflix, highlighting the security risks of iot devices.
4. Coping Strategies
• Deploy DDoS protection services to filter malicious traffic.
• Use a Content Delivery network (CDN) to distribute traffic.
• Configure load balancers to increase server processing capacity.
• Monitor network traffic to detect and respond to anomalies in time.
Insider Threats
1. Definition of Insider Threat
Insider threats come from authorized users (e.g., employees, contractors) within an organization who may abuse their privileges due to malicious, negligent, or manipulated by external attackers, resulting in data leakage or system damage.
2. Type of Threat
• Malicious insiders: Intentionally stealing data or compromising systems for profit.
• Negligent employees: Due to lack of security awareness, misoperation leads to vulnerability exposure.
• Hijacked accounts: Attackers control internal accounts through phishing or credential theft.
3. Hazards
Insider threats are difficult to detect and may bypass traditional firewalls and intrusion detection systems. In 2021, a well-known tech company lost hundreds of millions of dollars due to an internal employee leaking source code.
4. Solid Defensive Measures
• Implement zero-trust architecture and verify all access requests.
• Monitor user behavior to detect abnormal operations.
• Conduct regular safety training to enhance staff awareness.
• Limit access to sensitive data to reduce the risk of leakage.
Post time: May-26-2025
