Web3 Security Guide: Clipboard Risks and Protection Strategies

In cases of stolen crypto assets, a common confusion is: how do private keys leak without being transmitted over the network? In fact, the leakage of private keys or mnemonic phrases is not limited to the cloud or online storage; seemingly "local and secure" operations can also become security risks. For example, copying and pasting to fill in private keys, storing them in notes, or taking screenshots—these routine actions can become entry points for hackers.

This article will delve into clipboard security issues, analyzing their principles and attack methods, and providing practical prevention recommendations, aimed at helping users build a stronger awareness of asset protection.

Clipboard Security Risks

The clipboard is a temporary storage space provided by the operating system for sharing data between different applications. When a user copies content, such as a wallet address, that information is temporarily stored in the clipboard until it is overwritten by new content or cleared.

The security risks of the clipboard mainly stem from two aspects:

1. Plain text storage: Most operating systems do not encrypt clipboard data by default, but store it in memory in plain text.

2. System API open access: Operating systems typically provide clipboard-related APIs that allow various applications to access clipboard content. This means that applications with the appropriate permissions (including text editors, browser extensions, input methods, screenshot tools, and even malware) can silently read or modify clipboard data in the background.

In addition, the clipboard content is not automatically cleared by default, which may remain accessible for a long time. If a user copies sensitive information but does not promptly overwrite or clear it, malware or third-party applications may have the opportunity to access this data.

Some specialized clipboard malware is dedicated to altering addresses. According to a 2024 report from the United Nations Office on Drugs and Crime, one type of malware commonly used by Southeast Asian criminal groups is called a "clipper." This type of software monitors the clipboard of infected systems and replaces the payment address during cryptocurrency transactions. Since wallet addresses are usually quite long, users may find it difficult to notice the address change, leading them to mistakenly transfer funds to an address controlled by the attacker.

Prevention Strategies

To effectively prevent clipboard attacks, the fundamental approach is to avoid copying sensitive information and to install professional antivirus software to prevent malware intrusion. Here are some specific protective suggestions:

1. Avoid copying sensitive information: Try not to fill in your private key or mnemonic phrase by copying and pasting.

2. Clear the clipboard in a timely manner: If you accidentally copy sensitive information, immediately copy a large unrelated content to overwrite the previous content and reduce the risk of being read.

3. Use a secure input method: It is recommended to use the system's built-in input method and turn off the "cloud sync" feature.

4. Regular system security checks: Use reliable antivirus software to regularly scan the system and remove potential malware.

5. Carefully manage browser extensions: Disable unnecessary extensions and conduct a risk assessment of permissions for newly installed extensions.

6. Transfer address verification: When making cryptocurrency transfers, it is essential to carefully verify the wallet address to prevent funds from being mistakenly transferred due to clipboard tampering.

7. Avoid exposing sensitive information to the internet: Do not store private keys or mnemonic phrases in places that may be connected to the internet, such as photo albums, cloud storage, social media collections, or phone notes.

If you suspect that the device has been infected, it is recommended to immediately transfer assets to a new secure wallet to prevent further loss.

Clipboard Cleaning Guide

The methods to clear the clipboard for major operating systems are as follows:

• macOS: Only save the current clipboard content; copying an irrelevant piece of content will overwrite the history.

• iOS: In addition to copying unrelated content, you can also create shortcuts to add the action of clearing the clipboard to the home screen for quick cleanup.

• Windows 7 and earlier versions: only save the current content, and copying new content will overwrite it.

• Windows 10/11: If the "Clipboard History" feature is enabled, you can press Win + V to view the history and click the "Clear All" button in the top right corner to delete all records.

• Android: Clipboard history is usually managed by the input method, and you can manually clear unwanted records by accessing the clipboard management interface of the input method.

Conclusion

Clipboard security issues are often overlooked, yet they are a high-frequency channel for sensitive information leaks. This article aims to remind users to reassess the potential risks of copy and paste operations, recognizing that local actions do not equate to absolute safety. Raising security awareness, developing good operating habits, and taking necessary protective measures are key to protecting digital assets. Only by staying vigilant in daily use, continuously reinforcing security awareness, and implementing basic protective measures can one truly ensure asset safety.