# Selfdestruct Removal Analysis 3

This follows from the [first](https://nbviewer.org/github/adompeldorius/selfdestruct-analysis/blob/main/analysis.ipynb) and [second](https://github.com/jwasinger/eth-selfdestruct-analysis) selfdestruct removal analysis reports.

As explained in previous reports, there are two use-cases which will be broken if `SELFDESTRUCT` is replaced with `SENDALL` using [EIP-4758](linky):
* upgradable contracts created using `CREATE2` which can be selfdestructed and a new contract deployed at the same address.
* ephemeral contract creators: contracts which were intended to be created and selfdestructed in the same transaction now remain deployed after executing `SENDALL`.

This document gives an overview of contracts on mainnet that are confirmed/probable upgradable and creators of ephemeral contracts. A contract is considered upgradable if it has been created using `CREATE2` and has a reachable `SELFDESTRUCT` opcode in its bytecode.

When determining whether a contract has a reachable `SELFDESTRUCT`, we want to detect solidity metadata appended to the contract bytecode. This can contain arbitrary bytes so any `SELFDESTRUCT` opcode in it must not be considered. The heuristic used here is to consider the metadata to be any bytes past two adjacent `0x00` and `0xa2` opcodes.

The dataset used can be reproduced using [these instructions](https://github.com/jwasinger/eth-selfdestruct-analysis-3).

**Note:** a contract is considered recently-active if it has been the sender/receiver of an internal call or transaction since block 15900000.

## Findings Summary

### Potentially-Upgradable Addresses

Total of 2058022 existing selfdestructable contracts were created by 404 creators with only `CREATE2` in their bytecode. 176110 were created by 304 creators with both `CREATE2` and `CREATE`. 144735 have non-zero eth balances and 39204 were recently-active.

##### Creators by Balance

42 addresses with non-zero Eth balances. Top 10:
| Address | Project/Description | Balance
| ---- | ---- | ----- |
0xb16c1342e617a5b6e4b631eb114483fdb289c0a4|sudoswap: Pair Factory|259.2
0x0000000000000eb4ec62758aae93400b3e5f7f18| MEV Bot |85.52
0xb233cb2f0dce57a56bf732767f45ffc8650186c5||17.32
0xdf024061cf701c02db0e2df32f160f12a660a396||3.5
0x0000000000a1c7212a1c129512d80eb30d14dc08||2.95
0xf9e8c18a855183246dbf19c8b249921fa64bd33c|ItoVault: Deployer|2.427
0x35efabf6e2d970a3bc3fa1de991ec63987c127bc||2.38
0x94edc4a3065a7a42db6c57614e513992b2eb3ee4||2
0xbb7f0d85299d7068c741b3c7ed7800ff40599cc0||1.404
0x36ae49add923625ac7a30a49e3bdbbd07827a0a1||1.263

##### Creators by Recent Activity

57 addresses with recent activity. Top 10:
| Address | Project/Description | Call Count
| ---- | ---- | ---- |
0x00000000003b3cc22af3ae1eac0440bcee416b40|MEV Bot|43428
0xb16c1342e617a5b6e4b631eb114483fdb289c0a4|sudoswap: Pair Factory|39916
0x0000000000004946c0e9f43f4dee607b0ef1fa1c||6187
0x03d37ad26961d79e52c3daea840c0095fb4729a7||2547
0xdf024061cf701c02db0e2df32f160f12a660a396||2328
0x7151b902537197fd79b920a33f42a765ee6504d5||1379
0x57e037f4d2c8bea011ad8a9a5af4aaeed508650f| Loopring (?) | 1114
0x6090a6e47849629b7245dfa1ca21d94cd15878ef|ENS: Old Registrar | 806
0x000000000000084e91743124a982076c59f10084|MEV Bot| 424
0xd672f1e3411c23edbb49e8eb6c6b1564b2bf8e17||361

### Previously-reinited Selfdestructable contract addresses with create2-containing creators

1992 selfdestructable contracts deployed by 89 creators.

##### Top Creators by Recent Activity

14 contracts were recently active. Top 10:

| Address | Project/Description | Call Count |
| ---- | ---- | ---- |
0x000000000000084e91743124a982076c59f10084|MEV Bot|424
0x813c2ccc69f68bb5080c1656504a423cedf609ac||40
0x00000000e82eb0431756271f0d00cfb143685e7b||20
0x4088123881a441b733ee4563f9bf141b0f07d46a||19
0x29c03561b5ef34b4290e2863ec495042ff70781f||16
0x61aad281762f173589e5fa007e28641e5724efb2||10
0x1530a652881c4435f7fbf7c00d0a05c22e80d6c3||8
0x683f4403f5ce87e3f53e352379e5ba62f00ae694||8
0x920a1b37e7983244e1b5e5e46f27b4da00d47347||8
0x1eab56260a4a11f758d0f1097a76c465e1ca1fca||4

##### Top Create2-containing Creators by Balance

9 contracts had non-zero balances:

| Address | Project/Description | Balance |
| ---- | ---- | ---- |
0x0000000000000eb4ec62758aae93400b3e5f7f18| MEV Bot | 85.52
0xbb7f0d85299d7068c741b3c7ed7800ff40599cc0| | 1.404
0x545ab070078a05d0a6743f88a5ba2ad262daabc3| | 0.8100
0x000000000000cb53d776774284822b1298ade47f| | 0.000001590
0xdc3c2c78ef0e11952af23dccd8e24a0a64c9d20e|| ~0
0x0031867b9965761f730389d50dfbebd26527b8eb||~0
0x0000000000007673393729d5618dc555fd13f9aa||~0
0x00000000004c46cecbb6b3c67de2d24fbf4dd487||~0
0x5eb332b005a40e0a63f0e0ed5232b1208aa7084a||~0

##### Top Created Contracts by Balance

35 contracts had non-zero balances. Top 10:

| Address | Project/Description | Creator | Eth Balance |
| ---- | ---- | ---- | ---- |
0x0000000000007f150bd6f54c40a34d7c3d5e9f56| MEV Bot | 0x55757942b19e543a7d4c909f952f5509b10b66b3| 855.7
0x0000000000000eb4ec62758aae93400b3e5f7f18| MEV Bot | 0xbad5531e175167cd89e8fdc099b3ec43d83c48b7|85.51
0x000000000035b5e5ad9019092c665357240f594e| MEV Bot | 0x5aaa33de85c9daea4f9e216be937409849f80ecd|43.43
0x0000000000a84d1a9b0063a910315c7ffa9cd248| MEV Bot | 0x76dd8699c128bc795479191de364e99b38b6375e|55.08
0x000000000000660def84e69995117c0176ba446e| MEV Bot | 0x3dd1c15a0aeb7a772fa0c90f4817731c8622ff83| 30.88
0x0000000099cb7fc48a935bceb9f05bbae54e8987| MEV Bot | 0x5aaa33de85c9daea4f9e216be937409849f80ecd|11.62
0xf2d47e78dea8e0f96902c85902323d2a2012b0c0||0x62261ae38d40bcd5ab3e44989161b70a91e4d7da|3.378
0x00000007d259e6b322766529ac387b53a1584724||0x545ab070078a05d0a6743f88a5ba2ad262daabc3|0.2868
0x0eae044f00b0af300500f090ea00027097d03000| MEV Bot | 0x1eab56260a4a11f758d0f1097a76c465e1ca1fca|0.1256
0x45503c34ee615c4ed5fe071fc6ccee06c049b1e3||0x2319c999808d589b5fb33349b182f000d281dc65|0.1

##### Top Created Contracts By Recent Activity

45 contracts with create2-containing creators were recently-active. Top 10:

| Address | Name/Description | Creator | Recent Call Count |
| --- | --- | --- | --- |
0x0eae044f00b0af300500f090ea00027097d03000|MEV Bot |0x1eab56260a4a11f758d0f1097a76c465e1ca1fca|159511
0x007933790a4f00000099e9001629d9fe7775b800||0x879a58c3ca50c8c5f5647d310a5d0b3adeffdd59|96653
0x24902aa0cf0000a08c0ea0b003b0c0bf600000e0||0x4cfeb2473d7c64ac9a0e5442581883c9d88822df|95746
0xe8c060f8052e07423f71d445277c61ac5138a2e5| MEV Bot | 0xc139f939ec6124da1c318a84662bc9791f80c461|95728
0x81153f0889ab398c4acb42cb58b565a5392bba95| MEV Bot |0x86ad374125c76826c35357813352df6d7be1fab7|93222
0x00000000a991c429ee2ec6df19d40fe0c80088b8||0x0be2ed3b069366b78d90e57c0dd1db756043919f|85383
0x000000000035b5e5ad9019092c665357240f594e| MEV Bot | 0x5aaa33de85c9daea4f9e216be937409849f80ecd|73261
0x0000000000007f150bd6f54c40a34d7c3d5e9f56| MEV Bot | 0x55757942b19e543a7d4c909f952f5509b10b66b3|69964
0x0000000000a84d1a9b0063a910315c7ffa9cd248| MEV Bot | 0x76dd8699c128bc795479191de364e99b38b6375e|64186
0xfd0000000100069ad1670066004306009b487ad7||0x2d055433247d668086ea4083be33b4a05a24ef50|49950

### Ephemeral Contract Creators

Total of 9811 alive contracts that have previously created ephemeral contracts. 429 have non-zero Eth balances. 60 were recently active.

##### Top Contracts by Recent Activity

| Contract Address | Name/Description | Internal/External Call Count |
| ---- | ---- | ---- |
0xdef1c0ded9bec7f1a1670819833240f027b25eff| https://www.0x.org/ | 1350533
0xa5025faba6e70b84f74e9b1113e5f7f4e7f4859f| https://poanetwork.github.io/multisender (broken link from etherscan contract source code)| 60828
0x4f4495243837681061c4743b74b3eedf548d56a5| https://axelar.network/ | 38334
0xc77ad0a71008d7094a62cfbd250a2eb2afdf2776| | 16928
0x2e1891de1e334407fafaab09ac545bb9e4099833||14763
0xb69d4de5991fa3ded39c27ed88934a106f0af19e||14763
0xcf0da9cea8403ff1e3ed6db93f3badc885c24522||14761
0xebe5cccc75b4ec5d6d8c7a3a8cee0d8c0e821584||14761
0x8b2550add3c5067ca7c03b84e1e37b14b35aa1e5||14159
0xd0c7a9d47704979273a527bcace42c9e01a69ec1||5448

##### Top Contracts By Balance

| Contract Address | Name/Description | Ether Balance |
| ---- | ----- | ---- |
0x66be1bc6c6af47900bbd4f3711801be6c2c6cb32|https://hakka.finance/ |1910
0xa5025faba6e70b84f74e9b1113e5f7f4e7f4859f|https://poanetwork.github.io/multisender (broken link from etherscan contract source code)| 245.7
0x36049d479a97cde1fc6e2a5d2cae30b666ebf92b|https://pine.finance/ | 8.9230
0xd412054cca18a61278ced6f674a526a6940ebd84|https://www.sorbet.finance/ |6.226
0xfc0f5114c9bd93b84598d836e4b0bdfb2eb2b1e1||4.924
0xbd2a43799b83d9d0ff56b85d4c140bce3d1d1c6c||3.445
0xdf024061cf701c02db0e2df32f160f12a660a396||3.488
0xbe4a176b0d18f1e158cc1a833383212f68327b51||2.909
0xb1a71b3526a3494857c4ef873f7702a11e2e3265||1.550
0x3f615ba21bc6cc5d4a6d798c5950cc5c42937fbd||1.50

##### Top Contracts Ranked by Number of Created Ephemeral Contracts
| Contract Address | Number of Ephemeral Contracts Created Since Genesis |
| ---- | ---- |
0xe9428d4a341ac20e9f2e6b95b12c9ad52733fcd9|939699
0xa998cf7ac9c2063c95e6f81a0b8f220520d5e81a|294462
0x5a4e849325e9b87bdb918bbe1bbafdea819bbefe|270380
0x70872019d755762700951f70057eed26992455f3|268527
0xf331ff3d2eaf9a2009dc935816665c962fe82757|207984
0x2c204d6970eb394e73868b37ad0913b597c6a391|120640
0x9c5941b0e22fc11bc2901d78a5913a47fd9c87e0|94542
0xb6fb5ee1c5c9249b064f54f2ecbcfe3a66591fa7|80997
0x8b259620560c73f44adc2a5e0cd2f65c6e26c260|78267
0xa83063e117298993c3a2346224fdfd7f2f13aba5|78162

Etherscan gave no indication what these addresses were/are used for.

## Interpretation

There are many selfdestructable contracts deployed on mainnet that could break with a blanket selfdestruct removal as proposed in [EIP-4758](https://eips.ethereum.org/EIPS/eip-4758). [EIP-6046](https://github.com/ethereum/EIPs/pull/6046) is an alternative approach which provides backwards-compatible behavior for many on-chain contracts that would be broken by 4758. However, it has edge-cases that need consideration/investigation.

Looking at recent on-chain usage and Eth balance are good ways to prioritize potentially-affected contracts for manual analysis. However, we have to consider consider cases where disabling a low-value/rarely-used upgradeable contract could lock value in other contracts that depend on it.

Further automated analysis is needed to identify how potentially-affected contracts are related to other on-chain contracts: looking at history of interactions and doing static analysis to identify likely-addresses in code/storage, identify cases where these could be the address argument to a `CALL*` might provide useful insights.