Phishing airdrop sites and fake NFT mints are one of the most dangerous security threats to occur within the crypto ecosystem. These hacks take advantage of token approvals-a staple feature utilized across all decentralized applications-to help their hackers access users' assets illicitly. With this, malicious actors can move tokens, take control of NFTs, or drain entire wallets without any further confirmations needed in mere moments.
The article explains how these scams work, why users are falling prey to them, and what kinds of precautions can reduce the risks.
Understanding Token Approvals: A Foundation of Web3 Interaction
What are token approvals?
Approvals, in general, give a smart contract permission to spend or move a user's tokens on behalf of that user. Many legitimate actions require such approvals, including:
Swapping of tokens in decentralized exchanges.
Transfer and mint NFTs
Staking or depositing tokens in DeFi platforms
Claiming legitimate rewards or airdrops
Interacting with blockchain games
Approvals exist to prevent users from having to sign a new transaction every time they want to transfer something, but the same convenience creates avenues for misuse when approvals are granted to malicious contracts.
Why Approvals Can Be Dangerous
Approvals can allow a contract to:
Spend unconstrained amounts of some token
Move NFTs from the user's wallet
Continue operating long after initial approval
Perform transfers without further user confirmation
This would become a tool for scammers to drain a wallet if given unknowingly.
How Fake NFT Mints Exploit Token Approvals
Fake NFT mint websites remain one of the most common wallet-draining tactics in Web3. They either impersonate actual projects or fabricate hype for new “limited-time” collections.
1. Sham Mint Buttons That Trigger Approval Requests
Instead, it will send a hidden approval request without initiating any minting transaction. The prompts may appear to be valid, but in reality, the approval will grant permission for the attacker to:
Spend a certain token
Access all NFTs under a user's wallet
Grant unlimited access to assets
Many users only pay attention to gas fees or the "mint" label, which means they completely miss the approval details.
2. Malicious Smart Contracts Disguised as Mint Contracts
Fake contracts may look just like real mint contracts but contain dangerous functions such as:
transferFrom() to transfer tokens
setApprovalForAll() to manage NFTs
Hidden transfer logic to sweep assets
Once the user has signed the transaction, the contract executes these functions—sometimes instantly.
3. Social Engineering and Hype Manipulation
Scammers count on psychological triggers:
Fake "Mint Live" announcements on social media
Compromised Discord accounts sharing urgent links
Spam bots commenting to pretend legitimacy
Claims of urgency, such as "Only 100 spots left!"
This pressure encourages users to interact with the contract in an insufficiently verified manner.
How Phishing Airdrop Sites Exploit Token Approvals
Airdrops attract millions of crypto users, so this also makes them targets in phishing scams. Fake airdrop sites impersonate well-known projects or completely invent fully fictitious ones.
1. Fake Eligibility Check Hides Approval Transactions
A common tactic is to prompt the user to “Check Eligibility.”
Instead, the website will display a transaction that represents a concealed approval. The thief then uses this to:
Spend tokens
Move assets to a different wallet
Long-term control over the user's funds
Legitimate airdrops rarely ask for token approvals.
2. Abuse of Infinite Approval Permissions
Most phishing sites request that users sign transactions granting infinite approval, a setting which allows the contract to spend all of a user's tokens indefinitely. The scammers wait until enough users sign these approvals, then execute a batch transfer to steal tokens in bulk.
3. Fake "Claim Rewards" Buttons Causing Transfers
What seems to be a claim button may veil the following dangerous functions:
Unlimited token spending approvals
NFT operator permissions
Direct token transfer logic
These actions would, to the uninitiated user, look exactly like claiming legitimate rewards.
4. Timing Attacks Based on Major Airdrop Announcements
Scammers create fake airdrop web pages in periods of high user interest, which usually occurs right after some real project announces new rewards. That way, their phishing pages seem more believable and attract more click-throughs.