A drive-by exploit is one of the most subtle and efficient ways for a criminal to infect your device. It doesn't rely on direct interaction — instead, it delivers malicious software without the user even realizing their device is compromised. Understanding how this process works can help you to limit high-risk actions and protect yourself online.
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Key takeaways
A drive-by exploit is a cyberattack that installs malware on your device without any clicks or downloads on your part, simply by exploiting security flaws when you visit a compromised site. They deliver malware like trojans, keyloggers, spyware, and botnet software, which are designed to spy on you and hijack your device access.
Drive-by downloads happen either through exploited browser or plugin vulnerabilities or through disguised pop-ups and fake updates that trick you into installing them yourself. A drive-by exploit is the method that breaches your system's vulnerabilities, while a drive-by download is the resulting stealth installation of malware.
An exploit kit is the hidden program that scans your device for weaknesses and can lurk undetected for weeks before criminals use it to steal data or hijack your device.
Avoid drive-by exploit attacks by using an antivirus solution, ad blockers, and spam filters, and regularly updating your software. Enterprises can reduce drive-by exploit risks by using dedicated solutions and policies like automated patch management, least privilege access, browser isolation, secure web gateways, split tunneling, and endpoint detection tools.
NordPass can help limit the damage of a drive-by exploit by keeping your credentials in an encrypted vault, autofilling logins to block keyloggers from tracking them, and alerting you about compromised data through its Data Breach Scanner.
What is a drive-by exploit?
A drive-by exploit is a type of cyberattack that compromises users’ devices without disrupting their browsing. Cybercriminals automatically install malicious software on their target’s device by exploiting security vulnerabilities. Once they’ve infected the device, they can gain access to it, see internal files, observe the user’s behavior, and silently interfere with its internal processes.
The initial infection of a drive-by exploit can be imperceptible — the target doesn’t have to click on a pop-up ad or a link. Instead, they might simply visit a spoofed website, and the criminal executes a hidden script to determine if the device can be exploited. By the time the victim suspects something's wrong, it’s already too late. Software being downloaded on a device without your knowledge is called a drive-by download.
How do drive-by downloads work?
Although many drive-by exploits run on automatic scripts, they sometimes need a trigger to be activated. As such, drive-by download attacks are classified as either unauthorized or authorized.
Unauthorized, or silent, drive-by downloads occur automatically when a user visits an infected website and the criminals exploit security gaps in a web browser, extension, plugin, or operating system.
Authorized downloads, also known as hidden payloads, take advantage of website elements like pop-ups and alerts. The user interacts with the pop-up and intentionally downloads a file. Criminals might make the file appear as part of bundleware or a routine software update file, luring the user to open it. However, once installed, it runs as malware in the background.
Drive-by downloads are often hidden using malicious online adverts known as malvertisements. Sometimes they need user interaction, but simply coming to a page that displays an infectious ad can trigger the download process.
Infectious websites are the main hosts of drive-by malware and usually take one of two forms. The hacker can design a website from scratch to initiate the download when the user visits it. They might use generative AI tools to make the website look more legitimate or imitate a real service provider. Another method is hijacking an existing platform by infiltrating its backend. Hackers can then rig the host with their own malicious code without the side admins noticing, and any user visiting the website becomes the target of the exploit kit.
What is an exploit kit?
An exploit kit is a piece of software that the attacker programs to avoid detection during a drive-by download. The device continues to operate normally even after the kit infects it. Criminals use exploit kits to probe the security functions of the device and search for weaknesses they can take advantage of.
Exploit kits can quietly run in the background for days or even weeks before the criminal launches the next stage of their attack. In the meantime, the malware continues to look for exploits. Eventually, criminals finally strike, stealing their victim’s private data or turning their device into an illegal botnet that can be used in DDoS attacks. By this point, it’s too late for the user to protect themselves.
Drive-by exploit vs. drive-by download: What’s the difference?
Drive-by exploits and drive-by downloads are closely related concepts within the same attack chain — the exploit is the mechanism used to deliver the download. Cybercriminals use drive-by attacks to get their targets to unknowingly install malware on their devices, creating a backdoor access to internal data.
A drive-by exploit specifically looks for and takes advantage of system vulnerabilities to execute malicious code without user interaction. The code is executed directly in the device memory, leaving no trace behind. Criminals tend to use drive-by exploits when they spot zero-day vulnerabilities because the malware can hide in the device even after the issue is fixed.
A drive-by download refers to any download that takes place automatically without the user’s knowledge. Drive-by downloads aren’t always malicious — regular software can run a benign update that doesn’t need user’s consent to take place. However, in the case of drive-by attacks, such downloads are always designed to cause harm.
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What types of malware are hidden in drive-by attacks?
Drive-by attacks use different types of malware — usually ones that can burrow deep in the system so they’re harder to detect.
Trojans. A Trojan horse virus is a type of malware that disguises itself to look like a legitimate app. A trojan drive-by download can look like an updated version of an app the user has installed on their device.
Remote access trojans (RATs). A remote access trojan is a specific type of malware that lets criminals remotely surveil their target’s device. They give complete access to the device, including user behavior, file storage, and app process management.
Keyloggers. A keylogger — or a touchlogger for smartphones and tablets — is malware that lets criminals observe their target’s keyboard and screen input. Keyloggers reveal what the user enters in hidden fields, like passwords or bank card numbers, compromising sensitive personal information.
Spyware. Spyware is used to collect data about the target, access their personal information, and share it with third parties. It exploits vulnerabilities in communication apps and usually goes undetected. However, spyware on mobile devices like iPhones can sometimes be disrupted with a simple reboot.
Ransomware. Ransomware is used to encrypt files on a device. The user is unable to open or interact with the files, and the only person capable of decrypting them is the criminal who demands a payment to reinstate access. AI-powered ransomware uses machine learning algorithms to identify vulnerabilities faster and automate the attacks more effectively.
Botnets. Botnet software can be sneakily installed on a device to force it to join a network of other compromised machines. Once they turn into bots, the whole network is used to execute DDoS attacks and spam campaigns. The user might notice worse performance but not realize their phone or computer has become part of a botnet.
How to avoid drive-by exploit attacks
Drive-by exploits are hard to catch, and by the time you realize your device is compromised, it might be too late to undo a lot of the damage. However, you can use cybersecurity tools to proactively protect your device against potential threats.
Ad blockers
Malvertising is the ideal delivery method for a drive-by exploit. Thousands of websites run on ad revenue, and ads are an easy way to drive the money in. Since the platforms don’t pick what content is displayed in the ad banners, and third-party checkers aren’t always effective, malvertisements can easily slip through the cracks. Pre-click malvertisements can launch drive-by downloads as soon as the ad loads on the page.
Ad blockers can prevent these downloads by limiting how many banners and pop-ups you're exposed to. Pre-click downloads launch when a malicious advert runs its scripts, but that process can’t be triggered if a blocker won’t let the ad load. You can also use script-blocking software that scans each new page for malicious coding. Although this might not protect you from all drive-by exploits, it can go a long way to combat the malvertising threat.
Spam filters
An ad blocker can stop malvertising-infested banners from running scripts, but hackers have other ways to get users to visit malicious websites. Phishing emails are an effective way to lure a target. Criminals disguise themselves as legitimate senders, like banks, telecom companies, or social media support teams, and urge users to open a link in the email to resolve an issue related to their account or personal data. If the user opens the link, the script activates, scouring the device for vulnerabilities.
Setting up spam filters on your inbox can help limit drive-by exploit email scams. The filters flag emails containing suspicious sender addresses and content, sending them to the spam folder. If you see an unflagged suspicious email, don’t interact with it by opening links. Flag the email manually, and block the sender. Be very cautious of emails warning you to change a password you didn't request, or claiming you won a prize in a competition you never entered.
Software updates
As tempting as it is to keep hitting the “Remind me later” button each time you have a pending software update, you really shouldn’t ignore these prompts. Exploit kits take advantage of weak spots in your device which are often created by outdated software and unpatched security gaps.
Keeping your operating systems and browsers updated can stop a drive-by download from exploiting your device even if the file appears on it. With security vulnerabilities patched, the exploit can’t get to work, and your files remain safe. Updates aren’t just limited to software — smaller add-ons, plugins, and browser extensions can also become access points. You might even want to consider upgrading your hardware to ensure it supports up-to-date versions of apps.
Antivirus software
People often assume they only need antivirus software for files they download, not for everyday browsing. However, as the dangers of malvertising and phishing show, you can come across viruses and other malware even on mainstream legitimate platforms. You might not even realize your device is compromised once it happens.
Strong antivirus protection adds an extra layer of security for your device and data. Some antiviruses can detect and block malware on websites, before they’re even downloaded on your device. Setting up an antivirus lets you easily quarantine suspicious files and spot malware that’s hiding deeper in the system.
Enterprise IT defenses
Drive-by exploits can effectively target corporate devices. If a company doesn’t impose robust security measures, one visit to a compromised website can put the entire device network at risk. To combat the threat of drive-by attacks, organizations can use a range of dedicated cybersecurity tools like:
Automated patch management — the process of using dedicated tools to identify and deploy missing updates and patches for software and operating systems.
Least privilege access management — the policy of granting users, applications, and devices the minimum level of required access permissions.
Browser isolation — a cybersecurity model that runs browser activity in an isolated environment, like a sandboxed container, to prevent malware and malicious script from reaching the user’s device.
Secure web gateways (SWG) — a security solution that checks and analyzes the user’s web traffic between the internet and the endpoint to prevent malicious access and protect against malware and data breach attempts.
Split tunneling — a virtual private network (VPN) feature that lets users route their traffic through an encrypted VPN tunnel. Selected apps or websites are allowed to bypass the tunnel and connect to the internet directly.
Centralized endpoint detection and response (EDR) — a security solution that monitors endpoint activity in real time, detects suspicious behavior, and enables automated responses to threats.
How can NordPass help mitigate exposure of drive-by exploits?
Drive-by exploits are hard to catch once they’re in play, and if your device has been compromised, you need reliable tools to protect your data from exposure. NordPass is a password manager that uses zero-knowledge architecture and XChaCha20 encryption to secure access to your login credentials, credit card details, and other sensitive information you want to protect.
You can secure your vault with a master password that only you know or biometric authentication. NordPass uses autofill to input your login credentials for you, meaning you don’t need to type them manually — and a keylogger can’t track what you haven’t typed. To know if any of your credentials are compromised, you can set up the Data Breach Scanner and get live alerts. Try NordPass and keep your credentials secure on all your personal devices.