Those launching zero-day attacks aren't a monolithic group; they have various motivations and belong to different categories. It's not just opportunistic hackers who are the problem; there's also a bustling black market where zero-day vulnerabilities and exploits are traded for large sums of money. Nation-state actors, too, are in the hunt for these flaws. Instead of disclosing them, they often stockpile these vulnerabilities to craft specialized zero-day exploits for use against adversaries, a practice that has drawn significant criticism for putting innocent organizations in jeopardy.
Cybercriminals typically seek financial gain, focusing on acquiring sensitive information or holding it for ransom by encrypting (ransomware) or threatening to release sensitive data, or both. State-sponsored actors and hacktivists use zero-day vulnerabilities to advance social or political causes, often aiming to gather sensitive data or publicize their mission. Corporate espionage is another driver, where companies may use exploits to gain a competitive edge by accessing confidential information from rivals. Lastly, these attacks can be tools for cyberwarfare, orchestrated by nation-states targeting another country's digital infrastructure via disruptive long- and short-term attacks to gain advantage against utilities, economic institutions, strategic investment, and intellectual property – including state secrets.
Zero-day exploits have a wide reach, targeting everything from operating systems and web browsers to hardware and IoT devices. This vast spectrum of target devices is used by victims, including:
· Everyday users who have a vulnerable system like an outdated browser.
· Owners of valuable business data or intellectual property.
· Large enterprises and organizations managing significant amounts of sensitive data.
· Government agencies that hold critical information regarding national security.
Targets can be specific or broad. Targeted zero-day attacks aim at high-value targets like government agencies or large corporations, while non-targeted attacks focus on exploiting any vulnerable system they can find. In the latter case, the objective is often to compromise as many users as possible, making no one truly safe from potential harm.
The backbone of a zero-day attack is built on several factors, including:
· Identifying a software vulnerability, which includes flaws in application execution.
· The vulnerability is not being publicly disclosed.
· Rapid development of an exploit of the vulnerability.
These factors are enablers for various harmful activities, but the delivery of exploit code is still needed to advance an attack. Delivery of an exploit can happen through various channels:
· Social Engineering: Attackers use a variety of high-touch means, including tailored email, social media, and other messages; an attacker will build a profile of a target to gain trust
· Phishing: Attackers use this method to deceive users into opening a malicious file or link via an email that appears legitimate but is actually from an attacker.
· Drive-by download: In this scenario, threat actors embed exploit code into a compromised yet seemingly legitimate website as a hidden element. When visitors navigate to the infected site, the exploit is downloaded and executed on their systems without their direct action or awareness. This technique is often used to carry out zero-day attacks, making use of zero-day vulnerabilities to infiltrate systems discreetly.
· Malvertising: In this strategy, malicious ads go through trusted ad networks. Merely clicking or hovering over these ads triggers the exploit code. Given that users tend to trust known websites, this is a cunning way to launch zero-day attacks.
· Spear Phishing: This technique targets specific end-users with highly personalized messages via email, text, or other platforms. Should an attacker gain access to a privileged account, the usefulness of an exploit is magnified within the target infrastructure. This could expand the reach of an attack beyond a company to include partners and other affiliated organizations.
These exploits can also be bundled into an “exploit pack,” which probes the system for multiple vulnerabilities and delivers the exploit where it will be most effective. Once the code is executed, it can cause a range of damage—from data theft to rendering the system inoperable. Given the stealthy and sophisticated nature of these attacks, they are often hard to detect and prevent, necessitating advanced zero-day attack prevention strategies.