What Is a Zero Click Attack?

A Zero Click attack exploits software vulnerabilities to carry out an attack without any user interaction. By taking advantage of a flaw, a hacker can install malware or perform other malicious actions on a target device without the victim having to click a link, open a malicious file, or take any other action.

How Do Zero Click Attacks Work?

Most remote device control methods rely on phishing or other social engineering tactics to trick users into clicking a malicious link or opening an infected file. This action triggers malicious code, allowing spyware to be installed on the device.

A Zero Click exploit is designed to work without any user interaction, meaning it must execute code on its own. Most Zero Click exploits target vulnerabilities in apps that receive and process untrusted data. Common examples include SMS apps, various messengers, email clients, and calling apps.

These apps accept data from untrusted sources and process it before displaying it to the user. If the data processing code contains an unpatched vulnerability, a specially crafted message can exploit this flaw, allowing a malicious message or call to execute harmful code on the device.

Receiving an email or SMS does not require any user interaction—smartphones display notifications based on the content of an SMS or other message before the user even decides to open and read it. A well-crafted malicious message can install malware, delete itself, and suppress notifications, leaving the user with no indication that an attack has occurred.

The Threat

Zero Click exploits pose a significant security threat to smartphones and other devices due to their stealth and high success rate. Traditional exploits require the user to click a malicious link or open a file, increasing the chance of detecting and responding to the threat. Zero Click exploits can silently infect a device or trigger a missed call notification from an unknown number.

Zero Click vulnerabilities are highly valued by all threat actors, including APT groups and nation-states. These exploits are typically used to deliver spyware that secretly collects information about individuals of interest to governments or espionage groups.

Types of Zero Click Exploits

Smartphones are the most common target for Zero Click attacks because they use a variety of communication apps, including SMS, calling, social media, and messaging apps. This provides a broad attack surface for hackers.

Some groups are well-known for discovering and using Zero Click exploits as hacking tools. For example, the NSO Group has developed exploits for several Zero Click vulnerabilities in iPhones, Android devices, and their apps. These vulnerabilities are used to spread Pegasus spyware, which is sold to governments for law enforcement, intelligence gathering, and, in many cases, surveillance of journalists, activists, and other individuals of interest to the state.

While NSO Group is the most famous provider of spyware using Zero Click vulnerabilities, it is not the only group with this capability. The company has direct competitors, and other cyber threat actors also have the ability to discover and weaponize Zero Click vulnerabilities.

How to Protect Yourself from Zero Click Exploits

The whole point of a Zero Click attack is to avoid detection by the user. Since infection happens without any interaction from the victim, the target has no way to identify or prevent the threat in real time. However, that doesn’t mean you can’t protect yourself from Zero Click attacks. Reducing the risk of Zero Click exploits requires proactive, preventive measures such as:

• Keep your apps and firmware updated. Zero Click exploits take advantage of unpatched vulnerabilities in operating systems and apps. Regularly updating your OS and apps helps reduce your exposure to attacks.
• Install anti-spyware and anti-malware solutions. Zero Click exploits are often used to deploy spyware and other malware on devices. Using security solutions that can detect and remove infections can help mitigate the impact of an exploit.
• Avoid unsafe apps. Apps downloaded from unofficial app stores are more likely to contain vulnerabilities that can be exploited. Only installing apps from trusted sources minimizes your risk of being hacked.

Zero Click attacks are a modern and highly effective form of cyber threat that can seriously undermine user security. To protect against Zero Click attacks, users should follow cybersecurity best practices. It’s also important to be aware of potential threats and stay informed about current trends in information security.

The importance of a proactive approach to digital security cannot be overstated. Only by combining technological measures with increased user awareness can we effectively address these threats and protect valuable data and devices from unauthorized access.