Stablecoins such as USDC and USDT are among the most widely used assets in the crypto industry. Traders, liquidity providers, and everyday users rely on them because they maintain value stability and move fast across platforms. The popularity also puts them in a position where they are prime targets for attacks. One of the easiest methods used by hackers includes taking advantage of a core feature of the ERC-based token system referred to as infinite approval.
Infinite approval gives a decentralized application permission to access and move a user's tokens without asking for repeated confirmations. While this feature exists to make transactions smoother, it has also opened the door to a wide range of wallet-draining attacks. When abused, it allows hackers to quietly withdraw stablecoins from a user's wallet without requiring further permission.
This article will explain how infinite approval works, how attackers use it against USDC and USDT holders, why stablecoins are especially attractive targets, and what users can do to stay safe.
Understanding Infinite Approval in ERC-Based Tokens
For any decentralized application to move any user's tokens, permission is required. Permission, in this case, is referred to as an approval. Normally, a user would be able to choose to approve only the exact amount they want to use. However, most platforms encourage users to select much broader options: infinite approval.
Why Infinite Approval Exists
Infinite approval was created for convenience. It helps users by:
Reducing repeated pop-ups
Gas-fee saving
Allowing smooth interaction with DeFi platforms
Making every swap or liquidity action not require approval confirmation
Simplified: Once a user gives infinite approval, the platform can move tokens at any time without asking again.
The Hidden Risk
If such permission is granted for a malicious platform or a compromised smart contract, an attacker will be able to move tokens at any time, and the user does not get any warnings during the withdrawal.
This is why infinite approval has become one of the most dangerous, misunderstood security issues within Web3.
Why Attackers Focus on Stablecoins (USDC & USDT)
Stablecoins are the number one assets targeted in infinite approval scams. The reasons are simple and very practical.
Stablecoins Hold Predictable Value
Stablecoins represent dollar-like value in crypto. Here's why hackers prefer them:
There is no price volatility
They can be used instantly
They are easy to launder or convert
Almost every wallet holds stablecoins
Most crypto users keep a balance of USDT or USDC on hand for:
Trading pairs
Farming
Lending
Fees
Market movements
That makes stablecoin approvals extremely common.
Approvals are often old and forgotten
Users interact with many platforms over time. They may have approved:
Old staking sites
Trial platforms
Forked versions of well-known dApps
Project testing
Dead websites
These permissions may be valid for an indefinite period. The attackers search for such forgotten approvals and misuse them.
Stablecoins Move Quickly Across Chains
When hackers steal stablecoins, they can quickly:
Bridge them
Change places
Mix them
Hide them in smart contract routes
This speed makes recovery extremely difficult.
How Infinite Approvals Attack Works: A Smooth Breakdown
Here is a simple, natural-flow explanation of how these attacks happen.
Step One: The User Visits a Fake or Compromised Platform
This might be:
A fake staking platform
A token swap scam page
A cloned website, looking similar to any famous dApp.
Airdrop fake website
A website shared by a scammer pretending to support
The website is asking for a token approval "to enable trading," "to access liquidity," or "to claim rewards."
Step Two: The User Signs an Approval Transaction
It looks normal.
Nothing suspicious appears.
The wallet displays a standard approval request.
But the approval is granted to a malicious contract, which the hacker controls.
Step Three: Infinite Access is Provided
The wallet of the user has now allowed the malicious contract to move unlimited amounts of USDC or USDT.
Step Four: The Attacker Moves the Tokens
The attacker calls the permission, not through the user's wallet but through their own; that is how they will be able to:
Move stablecoins from the victim's wallet
Send them to a wallet of their own
Multiple transfers with no user confirmation
The victim receives no warning.
The signature is not required from the wallet.
The blockchain considers this a valid action since the user gave permission for it.
Step Five: The stolen stablecoins are laundered
Attackers immediately transfer the funds across:
Multi-chain bridges
Mixers
Decentralized Exchanges
Routing contracts
In a matter of moments, the money is virtually irretrievable.