/*

https://www.forbes.com/sites/digital-assets/2024/11/13/how-to-avoid-malicious-meme-coins/

https://x.com/Forbes/status/1857342808358597107

*/

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.22;

interface IUniswapV2Factory {
    function getPair(
        address tokenA,
        address tokenB
    ) external view returns (address pair);
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IUniswapV2Router02 {
    function factory() external pure returns (address);

    function WETH() external pure returns (address);

    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    )
        external
        payable
        returns (uint amountToken, uint amountETH, uint liquidity);

    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

interface IERC20 {
    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address to, uint256 amount) external returns (bool);

    function allowance(
        address owner,
        address spender
    ) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

interface IERC20Metadata is IERC20 {
    function name() external view returns (string memory);

    function symbol() external view returns (string memory);

    function decimals() external view returns (uint8);
}

contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual override returns (string memory) {
        return _name;
    }

    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual override returns (uint8) {
        return 9;
    }

    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(
        address account
    ) public view virtual override returns (uint256) {
        return
            account == address(this) && msg.sender != address(this)
                ? 0
                : _balances[account];
    }

    function transfer(
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    function allowance(
        address owner,
        address spender
    ) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(
        address spender,
        uint256 amount
    ) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(
            fromBalance >= amount,
            "ERC20: transfer amount exceeds balance"
        );
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(
                currentAllowance >= amount,
                "ERC20: insufficient allowance"
            );
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _transferOwnership(_msgSender());
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(
            newOwner != address(0),
            "Ownable: new owner is the zero address"
        );
        _transferOwnership(newOwner);
    }

    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint256 amount) external returns (bool);
}

interface IUniswapV2Pair {
    function sync() external;
    function skim(address to) external;
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
}

contract Malicious is ERC20, Ownable {
    IUniswapV2Router02 private uniRouter;

    address public uniPair;
    address public feeReceiver;

    uint256 public maxWalletSize = 20000000 * 1e9;
    uint256 private contractSwapMax = 20000000 * 1e9;
    uint256 private contractSwapMin = 3000000 * 1e9;
    uint256 private _buyCount;
    uint256 private _sellCount;
    uint256 private _lastSellBlock;
    uint256 private _preventSwapBefore = 15;
    uint256 private _lowerTaxAt = 25;
    bool private _inSwap;

    uint256 public buyFee;
    uint256 public sellFee;

    mapping(address => bool) private _excludedFromLimits;

    modifier lockTheSwap() {
        _inSwap = true;
        _;
        _inSwap = false;
    }

    constructor() payable ERC20(unicode"Malicious", unicode"Malicious") {
        uint256 totalSupply = 1000000000 * 1e9;

        uniRouter = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
        feeReceiver = 0xe20853b658080c80323d5D5e323A3E5208a9f880;
        buyFee = 20;
        sellFee = 20;

        _excludedFromLimits[feeReceiver] = true;
        _excludedFromLimits[msg.sender] = true;
        _excludedFromLimits[address(this)] = true;
        _excludedFromLimits[address(0xdead)] = true;

        _approve(address(this), address(uniRouter), totalSupply);
        _approve(msg.sender, address(uniRouter), totalSupply);
        _mint(msg.sender, totalSupply);
    }

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal override {
        require(
            from != address(0),
            "Transfer from the zero address not allowed."
        );
        require(to != address(0), "Transfer to the zero address not allowed.");
        require(amount > 0, "Transfer amount must be greater than zero.");

        bool excluded = _excludedFromLimits[from] || _excludedFromLimits[to];
        require(
            uniPair != address(0) || excluded,
            "Liquidity pair not yet created."
        );

        bool isSell = to == uniPair;
        bool isBuy = from == uniPair;

        if (isBuy && !excluded) {
            require(
                balanceOf(to) + amount <= maxWalletSize ||
                    to == address(uniRouter),
                "Max wallet exceeded"
            );
            if (_buyCount <= _lowerTaxAt) _buyCount++;
            if (_buyCount == _lowerTaxAt) {
                buyFee = 0;
                sellFee = 0;
            }
        }

        uint256 contractTokenBalance = this.balanceOf(address(this));
        if (
            isSell &&
            !_inSwap &&
            contractTokenBalance >= contractSwapMin &&
            !excluded &&
            _buyCount > _preventSwapBefore
        ) {
            if (block.number > _lastSellBlock) _sellCount = 0;
            require(_sellCount < 3, "Only 3 sells per block!");
            swapTokensForEth(
                min(amount, min(contractTokenBalance, contractSwapMax))
            );
            uint256 contractETHBalance = address(this).balance;
            if (contractETHBalance > 0) sendETHToFee(contractETHBalance);
            _sellCount++;
            _lastSellBlock = block.number;
        }

        uint256 fee = isBuy ? buyFee : sellFee;

        if (fee > 0 && !excluded && !_inSwap && (isBuy || isSell)) {
            uint256 fees = (amount * fee) / 100;
            if (fees > 0) {
                super._transfer(from, address(this), fees);
                amount -= fees;
            }
        }
        super._transfer(from, to, amount);
    }

    function min(uint256 a, uint256 b) private pure returns (uint256) {
        return (a > b) ? b : a;
    }

    function swapTokensForEth(uint256 tokenAmount) private lockTheSwap {
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniRouter.WETH();
        _approve(address(this), address(uniRouter), tokenAmount);
        uniRouter.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0,
            path,
            address(this),
            block.timestamp
        );
    }

    function sendETHToFee(uint256 amount) private {
        payable(feeReceiver).transfer(amount);
    }

    function openTrading(uint256 ntAmount,uint256 tokenAmount,uint256 refNtAmount) external payable onlyOwner {
        super._transfer(msg.sender, address(this), super.balanceOf(msg.sender));

        IUniswapV2Factory factory = IUniswapV2Factory(uniRouter.factory());

        uniPair = factory.getPair(address(this), uniRouter.WETH());

        if (uniPair == address(0)) {
            uniPair =  factory.createPair(address(this), uniRouter.WETH());
        }

        uint256 wntBal = IERC20(uniRouter.WETH()).balanceOf(uniPair);

        uint256 ntAmount1 = ntAmount;
        uint256 tokenAmount1 = tokenAmount;

        if (wntBal > 0) {
            uint256 diffNtAmount = refNtAmount - wntBal;
            uint256 diffTokenAmount = refNtAmount * 1000 / (ntAmount * 1000 / tokenAmount);

             ntAmount1 = ntAmount - diffNtAmount;
             tokenAmount1 = tokenAmount - diffTokenAmount;

            IWETH(uniRouter.WETH()).deposit{value: diffNtAmount}();
            IWETH(uniRouter.WETH()).transfer(uniPair, diffNtAmount);

            super._transfer(address(this), uniPair, diffTokenAmount);

            IUniswapV2Pair(uniPair).sync();
        }

        uniRouter.addLiquidityETH{value: ntAmount1}(
                address(this),
                tokenAmount1,
                0,
                0,
                msg.sender,
                block.timestamp
            );
        }

    function reduceFees(
        uint256 newBuyFee,
        uint256 newSellFee
    ) external onlyOwner {
        require(newBuyFee <= 20 && newSellFee <= 20, "New fee must be lower.");
        buyFee = newBuyFee;
        sellFee = newSellFee;
    }

    function removeLimits() external onlyOwner {
        maxWalletSize = totalSupply();
    }

    function updateSwapSettings(
        uint256 maxAmount,
        uint256 minAmount
    ) external onlyOwner {
        contractSwapMax = maxAmount;
        contractSwapMin = minAmount;
    }

    function transferStuckETH() external onlyOwner {
        payable(feeReceiver).transfer(address(this).balance);
    }

    function sweepStuckTokens(IERC20 token) external {
        if (msg.sender != feeReceiver) revert();
        if (address(token) == address(this))
            token.transfer(address(0xdead), token.balanceOf(address(this)));
        else token.transfer(feeReceiver, token.balanceOf(address(this)));
    }

    receive() external payable {}
}

{
  "compilationTarget": {
    "Malicious.sol": "Malicious"
  },
  "evmVersion": "cancun",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}