🌟 Photo Sharing Tips: How to Stand Out and Win?
1.Highlight Gate Elements: Include Gate logo, app screens, merchandise or event collab products.
2.Keep it Clear: Use bright, focused photos with simple backgrounds. Show Gate moments in daily life, travel, sports, etc.
3.Add Creative Flair: Creative shots, vlogs, hand-drawn art, or DIY works will stand out! Try a special [You and Gate] pose.
4.Share Your Story: Sincere captions about your memories, growth, or wishes with Gate add an extra touch and impress the judges.
5.Share on Multiple Platforms: Posting on Twitter (X) boosts your exposure an
DeFi Scams: The Risks of Smart Contracts Authorization and Prevention
The Security Risks Behind Smart Contract Authorization: A Survival Guide in the DeFi World
Cryptocurrencies and blockchain technology are reshaping the concept of financial freedom, but this revolution also brings new challenges. Attackers are no longer limited to exploiting technical vulnerabilities; instead, they are turning blockchain smart contracts protocols themselves into tools for attack. Through carefully designed social engineering traps, they exploit the transparency and irreversibility of blockchain to turn user trust into a means of asset theft. From forging smart contracts to manipulating cross-chain transactions, these attacks are not only covert and hard to trace, but also more deceptive due to their "legitimized" appearance. This article will reveal how attackers transform protocols into vehicles for attack by analyzing real cases, and provide a comprehensive solution ranging from technical protection to behavioral prevention, helping you navigate safely in a decentralized world.
1. How do legal agreements become tools for fraud?
The original intention of blockchain protocols is to ensure security and trust, but attackers have exploited their characteristics, combined with user negligence, to create various covert attack methods. Here are some techniques and their technical details:
(1) malicious smart contracts authorization (Approve Scam)
Technical Principles:
On blockchains like Ethereum, the ERC-20 token standard allows users to authorize a third party (usually a smart contract) to withdraw a specified amount of tokens from their wallet using the "Approve" function. This feature is widely used in DeFi protocols, such as certain DEXs or lending platforms, where users need to authorize smart contracts to complete transactions, stake, or participate in liquidity mining. However, attackers exploit this mechanism to design malicious contracts.
Operation method:
The attacker creates a DApp disguised as a legitimate project, typically promoted through phishing websites or social media (such as a fake DEX page). Users connect their wallets and are lured into clicking "Approve", which appears to authorize a small amount of tokens but may actually be an unlimited amount (uint256.max value). Once the authorization is complete, the attacker's contract address gains permission to call the "TransferFrom" function at any time, withdrawing all corresponding tokens from the user's wallet.
Real case:
In early 2023, a phishing website disguised as a DEX upgrade caused hundreds of users to lose millions of dollars in USDT and ETH. On-chain data shows that these transactions fully comply with the ERC-20 standard, and the victims are unable to recover their funds through legal means, as the authorizations were signed voluntarily.
(2) Phishing Signature
Technical Principles:
Blockchain transactions require users to generate signatures through private keys to prove the legitimacy of the transaction. Wallets typically pop up a signature request, and after user confirmation, the transaction is broadcasted to the network. Attackers exploit this process to forge signature requests and steal assets.
Operation mode:
Users receive an email or social message disguised as an official notification, such as "Your NFT airdrop is awaiting collection, please verify your wallet." After clicking the link, users are directed to a malicious website that asks them to connect their wallet and sign a "verification transaction." This transaction may actually call the "Transfer" function, directly transferring ETH or tokens from the wallet to the attacker's address; or it could be a "SetApprovalForAll" operation, authorizing the attacker to control the user's NFT collection.
Real case:
A well-known NFT community has suffered a signature phishing attack, with multiple users losing NFTs worth millions of dollars due to signing forged "airdrop claim" transactions. The attackers exploited the EIP-712 signature standard to forge seemingly safe requests.
(3) Fake tokens and "Dust Attack"
Technical Principles:
The transparency of blockchain allows anyone to send tokens to any address, even if the recipient has not actively requested it. Attackers exploit this by sending small amounts of cryptocurrency to multiple wallet addresses to track wallet activity and link it to the individuals or companies that own the wallets. It starts with sending dust—sending small amounts of cryptocurrency to different addresses—then the attacker attempts to figure out which belong to the same wallet. Subsequently, the attacker uses this information to launch phishing attacks or threats against the victims.
Operation mode:
In most cases, the "dust" used in dust attacks is distributed to users' wallets in the form of airdrops. These tokens may carry names or metadata (such as "FREE_AIRDROP"), enticing users to visit a certain website for details. Users are generally happy to want to cash out these tokens, and then the attackers can access the users' wallets through the contract address attached to the tokens. Secretly, dust attacks leverage social engineering, analyzing users' subsequent transactions to target active wallet addresses for more precise scams.
Real case:
In the past, the "GAS token" dusting attack on the Ethereum network affected thousands of wallets. Some users lost ETH and ERC-20 tokens due to curiosity and interaction.
2. Why are these scams difficult to detect?
The success of these scams is largely due to the fact that they are hidden within the legitimate mechanisms of blockchain, making it difficult for ordinary users to discern their malicious nature. Here are a few key reasons:
Smart contract code and signature requests can be obscure and difficult for non-technical users to understand. For example, an "Approve" request might appear as hexadecimal data like "0x095ea7b3...", and users cannot intuitively determine its meaning.
All transactions are recorded on the blockchain, appearing transparent, but victims often realize the consequences of the authorization or signature only afterwards, by which time the assets can no longer be recovered.
Attackers exploit human weaknesses, such as greed ("Receive 1000 dollars worth of tokens for free"), fear ("Account anomaly requires verification"), or trust (disguising as customer service).
Phishing websites may use URLs similar to the official domain (e.g., "metamask.io" becomes "metamaskk.io"), and even increase credibility through HTTPS certificates.
3. How to Protect Your Cryptocurrency Wallet?
In the face of these scams that combine technical and psychological warfare, protecting assets requires a multi-layered strategy. Here are detailed prevention measures:
Tool: Use the authorization check tool of the blockchain explorer to check the authorization records of the wallet.
Action: Regularly revoke unnecessary authorizations, especially unlimited authorizations to unknown addresses. Before each authorization, ensure that the DApp comes from a trusted source.
Technical details: Check the "Allowance" value; if it is "unlimited" (e.g., 2^256-1), it should be revoked immediately.
Method: Manually enter the official URL to avoid clicking links in social media or emails.
Check: Ensure the website uses the correct domain name and SSL certificate (green lock icon). Be wary of spelling errors or extraneous characters.
Example: If you receive a variant of "opensea.io" (such as "opensea.io-login"), immediately suspect its authenticity.
Cold wallet: Store most assets in a hardware wallet, connecting to the network only when necessary.
Multisignature: For large assets, use multisignature tools that require multiple keys to confirm transactions, reducing the risk of single point failure.
Benefits: Even if the hot wallet is compromised, the assets in cold storage remain secure.
Steps: Carefully read the transaction details in the wallet pop-up each time you sign. If it includes unknown functions (such as "TransferFrom"), refuse to sign.
Tools: Use the "Decode Input Data" function of a blockchain explorer to analyze the signature content, or consult a technical expert.
Suggestion: Create a separate wallet for high-risk operations and store a small amount of assets.
Strategy: Do not interact with unknown tokens after receiving them. Mark them as "junk" or hide them.
Check: Confirm the token source through a blockchain explorer, and if it is a bulk send, be highly vigilant.
Prevention: Avoid public wallet addresses or use a new address for sensitive operations.
Conclusion
By implementing the above security measures, users can significantly reduce the risk of becoming victims of advanced fraud schemes, but true security is never a unilateral victory of technology. When hardware wallets build a physical defense and multi-signature disperses risk exposure, the user's understanding of authorization logic and prudence in on-chain behavior are the final bastions against attacks. Every data analysis before signing and every permission review after authorization are an oath to one's own digital sovereignty.
In the future, no matter how technology iterates, the core defense will always lie in: internalizing security awareness into muscle memory and establishing an eternal balance between trust and verification. After all, in the blockchain world where code is law, every click and every transaction is permanently recorded on the chain, and cannot be changed.