What is an exploit, and how can you avoid them?

Exploits work in a similar way, but digitally. They allow hacks to bypass your security systems. So what is an exploit? How do they work? And how can you avoid them?

What is an exploit?

An exploit is the process of using system vulnerabilities to attack users or organizations and then gain unauthorized access to their systems or inject viruses. The exploit’s aim is 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.

Exploits can target various levels of your digital environment. It can use your hardware and software vulnerabilities, intercept the whole network or trick company’s staff by using social engineering. A security exploit can also happen offline. For example, a hacker can enter a restricted area by tailgating or just fooling the gatekeeper and steal some confidential data once inside.

So as you see, an exploit is quite a broad term, and hackers try various attack vectors to make it work. For example, they can access your system, then gain additional privileges until getting root access. They can also inject malware into your device, put malicious scripts into websites or ads, perform a DDoS attack, and disrupt a service’s activities.

Vulnerability vs. exploit

"Exploit" and "vulnerability" are not interchangeable terms. Basically, 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.

We can draw a parallel with offline criminal activities here. For example, a pickpocket can see that your purse sticks out of your pocket (a vulnerability). They can then secretly snatch the purse (exploiting that vulnerability).

Hackers often use exploit kits to discover vulnerabilities automatically. This is a software which can detect known vulnerabilities in users' systems. After scanning a device and discovering these weaknesses, the exploit kit can inject malware. Ransomware quite often spreads through exploit kits.

There is a so-called window of vulnerability exploit, a period between software release containing a vulnerability and releasing a patch to the public. When developers spot a vulnerability, they try to be quick to patch it so that hackers won’t notice and exploit it. However, when a patch is released, there is no guarantee that all the users will immediately install the update, so the vulnerability window can get prolonged.

Types of exploits

Similarly to other types of cyberattacks, exploits can be classified in different ways. The most common is the two-fold classification of known vulnerabilities and zero-day exploits:

• Known vulnerabilities. Imagine that a developer has found a vulnerability in their app or service and released an update to fix it. They will list the vulnerability in the Common Vulnerabilities and Exposures (CVE) index so that everybody knows about the issue and how to combat it. However, if users then forget to update their software, hackers can still exploit the security flaw before its patched.
• A zero-day exploit. A zero-day exploit is an exploit still undiscovered by developers. The name implies that developers have zero-days to patch it as the hackers already know about it and can exploit it at any time. When hackers discover such weak spots, they try to keep them unknown for as long as possible to exploit them for long periods. Such exploits are really dangerous as there are no patches for them (at least until they become known).

We can also classify them according to the ways they occur:

• Remote exploit. These exploits work over a network and exploit a vulnerability without prior access to the system. Such attacks are impersonal and can be done to lots of users. For example, a hacker can scan a server remotely, get access to it, then use a local exploit to inject malware.
• Local exploit. This exploit needs prior access to a vulnerable system and increases hacker’s privileges to a higher level.
• Client exploit. Client exploits involve direct interaction with the targeted device’s user, so often rely on social engineering tactics. In these situations, a hacker might contact a victim, pretend to be someone else, and convince them to give away personal information or passwords.

How to prevent exploits

Here are a few prevention methods, which can help you to avoid exploits:

• Use reliable security software. Make sure to use reliable security software with all recent updates installed. For example, a VPN can help you to prevent man-in-the-middle attacks and DNS spoofing. NordVPN’s Threat Protection Pro feature will give you ad blocking, shield you from trackers, and protect you from malware.
• Always update your software. As we mentioned before, exploits can often occur when people put off updating their software. The longer you wait to download the latest security patch for you browser or operating system, the longer hackers have to penetrate through 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 hackers to “brute-force” their way into your account. Check out our NordPass tool for easy and secure password storage.
• Use common sense to avoid 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.
• Use end-to-end encryption. Your data will be safe even if someone gets hold of it as they won’t have the private key to access it. This means that even if your data travels insecure channels it stays protected from interceptors as they won’t be able to access it. Check whether this feature is implemented in the apps you use to share or exchange sensitive data.