What is an exploit?
An exploit is a piece of code, a chunk of data, or a program designed to take advantage of a computer’s or a system’s bugs or vulnerabilities. Cybercriminals use exploits to attack users or organizations and then inject malware or gain unauthorized access to their computer networks.
Exploits are meant to violate the so-called CIA triad, which stands for confidentiality, integrity, and availability. The triad forms the basis for your security practices — you should keep your data confidential, maintain its integrity, and make it available for people with legitimate access.
How does an exploit work?
Exploits work by targeting vulnerabilities within a system’s software or hardware. Here's how they typically work:
01
Identifying a vulnerability
A hacker identifies a flaw in the system (like a bug in the code, misconfiguration, or weak security practices).
02
Creating an exploit
The hacker creates an exploit, a piece of code or data, that targets the vulnerability.
03
Gaining access
Once the exploit is executed, the attacker gains unauthorized access to the system.
04
Escalating privileges
Some exploits allow their creators to escalate privileges, giving them even wider access to the system.
Exploit strategies
Using exploit chains that combine multiple vulnerabilities to break into a system. An attacker may first use an exploit to gain access to a vulnerable application and then follow it up with another exploit to escalate their privileges and gain deeper access to the network.
Using exploit kits that come pre-packaged with multiple exploits, which cybercriminals can use to automate their attacks. These kits offer a range of exploits that discover vulnerabilities on their own and target them, often with ransomware. Exploit kits make it easier for novice hackers to attack various systems without having advanced technical knowledge.
Using exploit-as-a-service to rent exploits from online marketplaces. This method of using exploits is even easier than using exploit kits. Attackers get a ready-to-use attack package, complete with tutorials and even customer support. It makes cybercrime significantly more accessible.
Using the heap spray method to bypass security mechanisms by flooding the system memory with malicious data. The onslaught of information changes how a program behaves, halts its security mechanisms, and allows the attackers to use their other exploits to enter the system more quickly.
What's the relationship between a vulnerability and an exploit?
"Exploit" and "vulnerability" are not interchangeable terms. A vulnerability is a weak spot in a system that hackers can discover, and an exploit is the act of using that weak spot to inject malware or access the system. But a vulnerability can also exist without being exploited. For example, a pickpocket can see that your wallet is sticking out of your pocket (a vulnerability), and they can choose to secretly snatch it (exploit that vulnerability).
Types of exploits in cybersecurity
Exploits’ classification depends on their characteristics. Generally, they are divided into known exploits and unknown (zero-day) exploits. However, they can also be grouped and named based on the specific vulnerability the exploits target.
Known exploits
Cybercriminals use known exploits for vulnerabilities that have been discovered and publicly documented. These exploits are usually listed in the CVE (Common Vulnerabilities and Exposures) database, which is the standard way to identify vulnerabilities in software and hardware systems. Once a vulnerability is classified as a known exploit, security patches or workarounds are made available to fix the issue as soon as possible.
Unknown, zero-day exploits
Zero-day exploits are vulnerabilities unknown to the software developer or security community. Attackers actively search for these vulnerabilities in order to exploit them before a fix or patch is available, making them particularly dangerous. The term “zero-day” refers to the fact that the developers have "zero days" to address the issue before it is exploited.
Exploit categories
Exploits can also be categorized based on the type of vulnerability they target:
- 1.
Hardware exploits target vulnerabilities in gadgets, like computers, routers, or USB devices. Attackers use these exploits to bypass security software, gain unauthorized access, or execute malicious code directly on the hardware level. For example, a hacker could use an USB memory stick to load spyware when it's plugged into a computer.
- 2.
Software exploits target vulnerabilities in software applications or operating systems. Attackers can manipulate bugs or flaws in code to gain unauthorized access, execute malware, or take over control. For example, a hacker could use a buffer overflow attack, where excess data makes a program overwrite its memory and expose information in the process. Similarly, an SQL injection attack uses malicious code to manipulate a database and access the sensitive data.
- 3.
Network exploits target weaknesses in network infrastructure or its communication protocols. Attackers aim to intercept and control network traffic, manipulating it to gain unauthorized access or launch attacks on the connected systems. Session hijacking attacks, for example, allow attackers to take control of someone’s internet session and impersonate them.
- 4.
Personnel exploits target human behaviors. Attackers manipulate people to gain access to information or systems — they exploit trust, ignorance, or carelessness to trick people into giving away sensitive data. Phishing attacks where hackers impersonate trusted individuals are the most common example of personnel exploits.
- 5.
Physical site exploits target physical security vulnerabilities of a building, allowing attackers to gain unauthorized access to restricted areas or sensitive devices. Tailgating (or piggybacking) is a common way of entering a restricted area — the attacker simply follows an authorized person inside, slipping through the door before it can close and lock.
How are exploits carried out?
The way exploits are carried out depends on the type of vulnerability and the attack method used:
Remote exploits
Remote exploits happen when an attacker gains access to a system remotely through the internet. These exploits use vulnerabilities in software or network configurations, allowing cybercriminals to inject malicious code into a target system without needing physical access.
Local exploits
Local exploits require the attacker to have some level of access to the target system, either by being logged in or having physical access. These exploits use weaknesses in the local environment: Flaws in operating systems, applications, or configuration settings.
Client exploits
Client exploits target software or applications running on the user's device, like web browsers, email clients, or messaging apps. Using these exploits most often involves a phishing attack that tricks users into downloading malware or unknowingly giving away their login details.
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What are the dangers of exploits?
Exploits can cause significant harm to both individual users and enterprises:
Unauthorized access
Exploits can allow attackers to gain unauthorized access to systems, networks, or sensitive data. This, in turn, leads to data breaches, stolen intellectual property, or exposure of private information.
Privilege escalation
Once an attacker gains initial access, they may use an exploit to escalate their privileges, granting them higher levels of access to the system. This enables them to take control of the entire system or network, often undetected.
Malware deployment
Exploits are commonly used to deliver viruses, ransomware, spyware, and other malware onto the targeted system. Once installed, the malware will steal data, lock files, or create backdoors for further attacks.
Data theft and loss
Exploits targeting vulnerabilities in applications or hardware can result in stolen personal or financial data. Attackers use this information for identity theft, fraud, blackmail, or further attacks.
Reputation damage
A successful exploit can harm a business’ reputation beyond repair, erode customer trust, and lead to financial losses due to legal liabilities, fines, or loss of revenue. But individual users also suffer reputational damage that’s emotionally taxing to recover from.
General disruption
Exploits can cause significant disruptions to business operations by compromising critical systems, shutting down services, or damaging infrastructure. But dealing with stolen data, overtaken accounts and devices, or identity theft is also very disruptive to individual users’ lives.
How to prevent exploits?
Even though exploits are a serious threat to both individual users and businesses, they are relatively easy to avoid.
Use reliable security software
Make sure to use security software that receives regular updates. For example, a VPN can help you to prevent man-in-the-middle attacks and DNS spoofing. NordVPN’s Threat Protection Pro™ feature will help you avoid phishing, scams, and malicious downloads.
Always update your software
Exploits often happen when you put off updating your software. The longer you wait to download the latest security patch for your browser or operating system, the more time hackers have to exploit your security loopholes.
Use strong passwords
Hackers can try to use password-cracking malware to access your system. But if you use complex passwords, combining randomized characters and unsequenced numbers, you can make it almost impossible for attackers to brute-force their way into your account.
Learn to recognize social engineering attacks
Do not open links, attachments, or messages from senders you don’t completely trust. Don’t download apps from unverified sources, and always research an app before you install it, even if it comes from a legitimate online store.
Your data will be safe even if someone gets hold of it — they won’t have the private key to unencrypt it. Always check whether end-to-end encryption is available in the apps you use to share or exchange sensitive data.
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