Hi I started do some experiments with blockchain using python and...Also

received such coins.
I was interested in what I've got and tried find out what I could do with it.
So, I read NOTE which is connected to the transactions and saw the following:Congratulations on getting TTC.Exchange at ttc55·com (1TTC = 55TRX) 到ttc55·com兌換
I browsed specified website and connect my wallet (TronLink) to it. Because on website I read that I would get 55TRX for each TTC. I switched off my head completely and connected my wallet. Balances in the wallet were about 50 TRX and 5 USDT. It's my experimental wallet, so I dont' care.
When wallet was connected I initiated TTC->TRX swap through specified website and signed transaction in wallet. Transaction was CONFIRMED and DONE but nothing happened besides website told me that TRX is not enough, I should try again. I did such tries 5 times and decided to check tronscan. In tronscan I saw 5 transaction with zero amounts but with triggerred USDT smart contract in TRON network transaction type: IncreaseApproval. And 5 transaction in Approval tab with transaction type: Trigger Smart Contracts.
I found in USDT contract StandardToken.sol the following function:
function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
And in TetherToken.sol the following:
function increaseApproval(address _spender, uint _addedValue) public whenNotPaused returns (bool) {
if (deprecated) {
return UpgradedStandardToken(upgradedAddress).increaseApprovalByLegacy(msg.sender, _spender, _addedValue);
} else {
return super.increaseApproval(_spender, _addedValue);
}
}
Do you know what these functions are for?
Of course I disconnected my wallet from this site and transfer almost all my assets to another account. But I want to understand what it was. I want to understand the mechanism. And as I describe earlier those transactions were total zero except energy and bandwidth of course. I spent energy and bandwidth.
But more interesting thing that end of the address of these scammers is:
TSEzmcnQe5kVzLAsj1kfakGjSwrk4UTj6t
And contact address for USDT is...:
TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t

I was about to report this but then I'm not sure about it