forefy

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forefy

forefy

@forefy

Over a decade of security research and engineering channeled into securing web3 ㅤ CTO @audit_wizard 🧙‍♂️🪄🪄 ㅤㅤㅤㅤㅤㅤㅤ Co-Founder @hackstackapp

Request an audit Katılım Aralık 2021
329 Takip Edilen583 Takipçiler
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forefy
forefy@forefy·
Auditing is finding bugs others missed. Evolution of solving smart contract security (aka how to find bugs in 2026): ❌ Static analysis is blind to logic ❌ Fuzzing may find logic bugs by accident, but is blind to integrations ❌ Invariant fuzzing covers logic + state, but blind to spec gaps and unknown invariants ❌ Formal verification proves what you specify, but blind to what you didn't specify ❌ Spec-to-code compliance catches spec gaps, but blind to implicit assumptions never written ❌ Human adversarial reasoning covers the rest - but doesn't scale ❌ AI pattern reasoning scales human thinking based on past patterns, but not novel ones ("This looks like a reentrancy. I've seen reentrancy before. check for reentrancy.") 👾👾👾 Then there was first-principles reasoning "This contract holds ETH. ETH can move. Who controls when it moves? What happens if it moves at an unexpected time? What state is inconsistent if that happens?" With Claude Code + Skills in 2026 we can remove the blind spot, but it requires: 🧠 deep domain expertise 🥷 creativity 💰 funds AI skills are the solution for first-principle reasoning. however, auditors ignore the 3 requirements. They do so by: ❌🧠 Skipping the domain expertise, and asking AI to generate the checklists ❌🥷 Skipping creativity by copying each others fully AI-generated logic ❌💰 Careless on token spend The alpha is that to find bugs in 2026 you need to work in researching the deep extra specific domain expertise, add your creativity and personal takes to it, and optimize it like every word matters (which it does). This doesn't scale right away but it does over time. Exactly how it's done today: 👉 3 terminal tabs, each running tmux with 2-4 claude code panes 👉 claude sonnet 4.6 🪨 caveman skill for token optimization 🧠 obsidian vault for memory and organization 👉 secret ingredient: research what you audit 🧪 occasional experiments with guest skills from our community's finest If you are doing this too, interested to learn and research together and want to hunt bugs - we should be friends Comment below, and I'll DM 🤍
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Seb ⚛️ ThisWeekInReact.com
Seb ⚛️ ThisWeekInReact.com@sebastienlorber·
npm user? ➡️ One small change to stay safe, FREE Add these aliases ➡️ pkg installs forbid using known malware I run this: - locally, to stay safe - in my CI to detect compromised transitive dependencies early for my lib consumers
Seb ⚛️ ThisWeekInReact.com tweet media
Feross@feross

@hasante_ Yes, we have Socket Firewall socket.dev/blog/introduci…

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forefy
forefy@forefy·
📝 supply-chainability term to describe how much your devs are prone to get rekt by a supply chain attack how much would you say is an average supplychainability % in a small dev team nowadays?
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forefy
forefy@forefy·
Claude Code steering behaviour that causes your agent to forget stuff: (for devs and auditors alike) > implement X >> Thinking... > oh also implement Y the latter creates an interrupt signal that will cause X to finish half-way, creating hidden slop FIX: > implement X >> Thinking... > side job: implement Y depending on the task it will auto trigger a background task or just be clearly instructed that this is not a steer but an added request Also token-efficient!
forefy@forefy

Agent Harness Engineering Pattern #8 Steering 🪂 (and I bet you didn't know you cared) Ever thought how it affects your chat when you're interrupting claude code mid-turn? Partial turn still in transcript >> Hi >> [interrupted] >> I mean bye All remains in context Good because: - Model can push back - "was 90% done, should I finish first?" - Can reference the cut itself e.g. "when I stopped you.." Bad because: - Many interruptions is filling the context window with junk - Late interrupt mean all prior tool calls still in window, still cost tokens‼️ 😱

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forefy
forefy@forefy·
forefy@forefy

I gave @VitalikButerin "A shallow dive into formal verification" article to the caveman skill haha You gotta love gen z knowledge consumption 👇🪨 🪨What it is Formal verification = math proofs machine can check. Lean language. AI writes proofs now. Paradigm shift happening in Ethereum + broader computing. 🪨Why care (this one is my favorite 😂😂) Bugs scary. Bugs in smart contracts → North Korea drain funds. Bugs in ZK proofs → steal silently, no trace. Powerful AI models automate bug discovery. Need stronger guarantees. 🪨Core idea Program is math object. Prove it behaves correctly = math theorem. Example: - Signal's X3DH key exchange proven as hard as DDH assumption - AES impl proven correct - Together → Signal encryption secure vs passive attackers End-to-end FV means: not just "protocol is secure in theory" - specific user code proven secure in practice. User checks statement claimed, not entire codebase. 🪨Key insight Safe programming = express intent multiple ways, verify all consistent. FV extends this infinitely: optimized impl + readable impl → verify match. 10 friends each write property list → check all pass. AI does all of it fast. 🪨 How to use today Don't write proofs by hand - too hard. Instead: - Ask AI write program in Lean (or assembly) - AI proves desired properties along way - Task self-verifying → let AI run hours unsupervised - You only check: final theorem statement matches what you wanted Best models for Lean proofs: Claude, Deepseek 4 Pro, Leanstral (119B, 6B active, runs locally ~15 tok/sec). 🪨 Limits - Easy forget to prove what actually matters - Easy sneak false assumptions into proofs - Unverified code parts still bite you - Even Lean itself can have bugs - Only value = clarity of theorem statement you check at end 🪨 Bottom line FV = "final form of software development" (Yoichi Hirai). AI makes it viable now. Write spec, AI proves code matches spec. Check statement, trust code.

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vitalik.eth
vitalik.eth@VitalikButerin·
Many people have claimed that with AI-assisted bug finding, secure code (and hence trustless anything) will be impossible. I have a much more optimistic take, and AI-assisted formal verification is a major part of the reason why: vitalik.eth.limo/general/2026/0…
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forefy
forefy@forefy·
I gave @VitalikButerin "A shallow dive into formal verification" article to the caveman skill haha You gotta love gen z knowledge consumption 👇🪨 🪨What it is Formal verification = math proofs machine can check. Lean language. AI writes proofs now. Paradigm shift happening in Ethereum + broader computing. 🪨Why care (this one is my favorite 😂😂) Bugs scary. Bugs in smart contracts → North Korea drain funds. Bugs in ZK proofs → steal silently, no trace. Powerful AI models automate bug discovery. Need stronger guarantees. 🪨Core idea Program is math object. Prove it behaves correctly = math theorem. Example: - Signal's X3DH key exchange proven as hard as DDH assumption - AES impl proven correct - Together → Signal encryption secure vs passive attackers End-to-end FV means: not just "protocol is secure in theory" - specific user code proven secure in practice. User checks statement claimed, not entire codebase. 🪨Key insight Safe programming = express intent multiple ways, verify all consistent. FV extends this infinitely: optimized impl + readable impl → verify match. 10 friends each write property list → check all pass. AI does all of it fast. 🪨 How to use today Don't write proofs by hand - too hard. Instead: - Ask AI write program in Lean (or assembly) - AI proves desired properties along way - Task self-verifying → let AI run hours unsupervised - You only check: final theorem statement matches what you wanted Best models for Lean proofs: Claude, Deepseek 4 Pro, Leanstral (119B, 6B active, runs locally ~15 tok/sec). 🪨 Limits - Easy forget to prove what actually matters - Easy sneak false assumptions into proofs - Unverified code parts still bite you - Even Lean itself can have bugs - Only value = clarity of theorem statement you check at end 🪨 Bottom line FV = "final form of software development" (Yoichi Hirai). AI makes it viable now. Write spec, AI proves code matches spec. Check statement, trust code.
vitalik.eth@VitalikButerin

Many people have claimed that with AI-assisted bug finding, secure code (and hence trustless anything) will be impossible. I have a much more optimistic take, and AI-assisted formal verification is a major part of the reason why: vitalik.eth.limo/general/2026/0…

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forefy@forefy·
DeFi attack vectors by funds lost - looked for ages for this slide so felt useful to share Thanks @blockthreat 🙏
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forefy@forefy·
The very core principal is that you start hunting on codebase that went through audits, contests, thousand of eyes, even onchain attackers failed to find an exploit This means that you have to dive deeper than anyone else either on a niche knowledge expertise or on a peripheral (e.g. condition the protocol does that is not obvious and affects state in a very unexpected way) Also read this: x.com/i/status/20538…
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Ayush Raj
Ayush Raj@yusha_raj·
@forefy @Hacker0x01 @Bugcrowd I was into Web2 security before, transitioned to Web3, and not back to square 1? Anything you have, opinion idea, could you please share? Anything that can help with the transition again, like should I hunt Web2 in Web3?
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forefy
forefy@forefy·
For all the auditors getting scared by this contests market shift - let me walk you through bugonomics history 🐛🪨⏬ 1⃣9⃣9⃣5⃣ Netscape (old browser) paid researchers for bugs which was radical at the time 2⃣0⃣1⃣2⃣ @Hacker0x01 and @Bugcrowd dominated the bounty space and no notion of contests they had private invite-only events which is close, but a contest model didn't fit large web2 companies e.g. Uber Airbnb etc - don't want 500 hackers hammering their servers at a single week 2⃣0⃣2⃣1⃣ @code4rena realized that contests are of different nature: - Smart contracts store loads of money directly, and get hacked like crazy - Smart contracts are "immutable" - once deployed must find bugs before launch - Open source means auditor can fully understand logic, not just probe blindly - More auditor attention, better results For protocols - contests costs more than bounty Let's think like a protocol for a second 🤔 contest = coverage, more eyes, pre-launch safety net - Pay $200k pool upfront - Runs 1-4 weeks - Payout regardless of findings quality (money still gone) bounty = sparse coverage, reactive not proactive - Pay $0 until valid bug reported - Only pay on confirmed severity - Treasury preserved until hit in bull markets - protocols don't want to get hacked, they spend what they can (contests + bounty after) in bear markets - same, but now protocols have no funds - bounty is cheaper 2⃣0⃣2⃣5⃣ bear market gets worse, AI spamming submissions left and right making triaging costs increase exponentially 2⃣0⃣2⃣6⃣ even worse - still bear market, MORE (way more) AI and there are less new protocols on top of it all That's why today we are back to web2-style bounties. The protocols that make real money, real impact. In 2015 people made a living of web2 bounties, this ain't different @immunefi @HackenProof @xyz_remedy all are live and kicking, and there's money on the table for you to take, harder than before, true - but since when hard stopped us?
forefy@forefy

🚨🚨 DAILYWARDEN IS DOWN 🚨🚨 DAILYWARDEN IS DOWN 🚨🚨 DAILYWARDEN IS DOWN!!! I guess we are all officially transitioning back to bounties now 😈😈 dailywarden.com Here's where I'd go to next 👇 hackenproof.com/programs?langu… immunefi.com/bug-bounty/?fi…

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forefy
forefy@forefy·
@hugoderby230593 @Hacker0x01 @Bugcrowd Bugs harder to find, because they're very rare and audited already, and you only sometimes get paid Program wait for your bugs for a long time rather than 2 weeks
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forefy
forefy@forefy·
Auditing is finding bugs others missed. Evolution of solving smart contract security (aka how to find bugs in 2026): ❌ Static analysis is blind to logic ❌ Fuzzing may find logic bugs by accident, but is blind to integrations ❌ Invariant fuzzing covers logic + state, but blind to spec gaps and unknown invariants ❌ Formal verification proves what you specify, but blind to what you didn't specify ❌ Spec-to-code compliance catches spec gaps, but blind to implicit assumptions never written ❌ Human adversarial reasoning covers the rest - but doesn't scale ❌ AI pattern reasoning scales human thinking based on past patterns, but not novel ones ("This looks like a reentrancy. I've seen reentrancy before. check for reentrancy.") 👾👾👾 Then there was first-principles reasoning "This contract holds ETH. ETH can move. Who controls when it moves? What happens if it moves at an unexpected time? What state is inconsistent if that happens?" With Claude Code + Skills in 2026 we can remove the blind spot, but it requires: 🧠 deep domain expertise 🥷 creativity 💰 funds AI skills are the solution for first-principle reasoning. however, auditors ignore the 3 requirements. They do so by: ❌🧠 Skipping the domain expertise, and asking AI to generate the checklists ❌🥷 Skipping creativity by copying each others fully AI-generated logic ❌💰 Careless on token spend The alpha is that to find bugs in 2026 you need to work in researching the deep extra specific domain expertise, add your creativity and personal takes to it, and optimize it like every word matters (which it does). This doesn't scale right away but it does over time. Exactly how it's done today: 👉 3 terminal tabs, each running tmux with 2-4 claude code panes 👉 claude sonnet 4.6 🪨 caveman skill for token optimization 🧠 obsidian vault for memory and organization 👉 secret ingredient: research what you audit 🧪 occasional experiments with guest skills from our community's finest If you are doing this too, interested to learn and research together and want to hunt bugs - we should be friends Comment below, and I'll DM 🤍
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forefy
forefy@forefy·
forefy@forefy

For all the auditors getting scared by this contests market shift - let me walk you through bugonomics history 🐛🪨⏬ 1⃣9⃣9⃣5⃣ Netscape (old browser) paid researchers for bugs which was radical at the time 2⃣0⃣1⃣2⃣ @Hacker0x01 and @Bugcrowd dominated the bounty space and no notion of contests they had private invite-only events which is close, but a contest model didn't fit large web2 companies e.g. Uber Airbnb etc - don't want 500 hackers hammering their servers at a single week 2⃣0⃣2⃣1⃣ @code4rena realized that contests are of different nature: - Smart contracts store loads of money directly, and get hacked like crazy - Smart contracts are "immutable" - once deployed must find bugs before launch - Open source means auditor can fully understand logic, not just probe blindly - More auditor attention, better results For protocols - contests costs more than bounty Let's think like a protocol for a second 🤔 contest = coverage, more eyes, pre-launch safety net - Pay $200k pool upfront - Runs 1-4 weeks - Payout regardless of findings quality (money still gone) bounty = sparse coverage, reactive not proactive - Pay $0 until valid bug reported - Only pay on confirmed severity - Treasury preserved until hit in bull markets - protocols don't want to get hacked, they spend what they can (contests + bounty after) in bear markets - same, but now protocols have no funds - bounty is cheaper 2⃣0⃣2⃣5⃣ bear market gets worse, AI spamming submissions left and right making triaging costs increase exponentially 2⃣0⃣2⃣6⃣ even worse - still bear market, MORE (way more) AI and there are less new protocols on top of it all That's why today we are back to web2-style bounties. The protocols that make real money, real impact. In 2015 people made a living of web2 bounties, this ain't different @immunefi @HackenProof @xyz_remedy all are live and kicking, and there's money on the table for you to take, harder than before, true - but since when hard stopped us?

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Talfao
Talfao@talfao1·
@forefy aa too much pessimism!
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forefy@forefy·
🚨🚨 DAILYWARDEN IS DOWN 🚨🚨 DAILYWARDEN IS DOWN 🚨🚨 DAILYWARDEN IS DOWN!!! I guess we are all officially transitioning back to bounties now 😈😈 dailywarden.com Here's where I'd go to next 👇 hackenproof.com/programs?langu… immunefi.com/bug-bounty/?fi…
forefy tweet media
forefy@forefy

🚨🚨 C4 SHUTS DOWN (and what does it mean) > since June last year @zellic_io did not take any profit to themselves for keeping @code4rena alive despite platform obvious costs > why? we can defer that Zellic's customers enjoyed the services there, and that its hell of a business lead-gen to be this middleman, even for free > bear market + AI submission spam is a bad combo, but even worse that it continues overtime without breathing air to many the OG stepping down might signal "contests are dead" (which was already the vibe with thedailywarden homepage) but to me it just says that it's a hard business running a contest platform nowadays if you're an auditor, don't use it as an excuse to give up - but take the lesson here that "easy" wins are no longer valuable - contests that pay need real criticals, real impact, hard research, niche focus areas and strengths its your time to shine ☀️ thanks @code4rena for reimagining crowdsourced security

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forefy@forefy·
@0xmishoko HAHA WOW! We're just back to bounties! this was the case 5 years ago for all security researchers
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mishoko ~/ ⛓
mishoko ~/ ⛓@0xmishoko·
@forefy geez, vigilseek not loading too. what are the alternatives?
mishoko ~/ ⛓ tweet media
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Auditware
Auditware@audit_wizard·
In 2022, we performed one of the first ever OpSec audits for a web3 company, pulling from over 7 years of experience securing the most sensitive and high value teams at companies like Apple and Amazon. We built a bespoke audit process from the ground up that covers all of the weak points that code and infra audits don't. Over the past 4 years we've reviewed OpSec for VCs, startups, mature companies, and teams ranging from 5 people to 50+. Including crypto-adjacent orgs with no on-chain presence, and crypto-native orgs with dozens of multi-sigs and hot wallets. We started with ad-hoc reviews tailored to each organization: Meet with the team to ask all the questions we could think of, build a threat model, and write a report highlighting risks and recommending mitigations. But we quickly learned that, while there are unique risks each team faces, much of the topics we covered were shared between orgs. We wrote guides for securing Discord servers, Twitter/X accounts, email servers, and developed both targeted and generalized trainings for whole teams. We also learned that these audits ran most smoothly with some sort of structure in place to define what each meeting should cover, who we needed to talk to in the org, and when we knew we were done. And when we spoke about OpSec to teams they didn't have a solid understanding of what it even meant or what the scope included. We built a very detailed internal process and set of resources outlining all of this. Since then, we've taken that internal playbook and refined it across multiple audits, each with their own unique risks and challenges. But this was something we felt we could not keep to ourselves. Last year, we converted that playbook into a comprehensive set of requirements, guides, and tools - all open source and free for anyone to use. We called it the Web3 OpSec Standard (W3OS). What sets W3OS apart from other OpSec resources is that it aggregates a comprehensive set of guidance into one place; presents everything as actionable checklists; and provides concrete guides for configuring platforms, setting up secure development environments, and training teams to stay secure. This year, we've also started building tools to support these guides and requirements and enable teams to take their OpSec seriously without having to build complex monitoring tools themselves. Auditware has been doing OpSec audits for over 10 years, we wrote the book on web3 OpSec, and we continue to build open source public goods for tackling OpSec issues because we truly believe that our industry cannot thrive without preventing the many, easily preventable security failures we have seen over the years. We highly encourage everyone to put these resources to good use and tighten up your OpSec before you have an incident! The best way to get started with this is making an account on our free OpSec collaboration platform platform, Sentry, which allows you to navigate W3OS requirements and guides with ease, track tasks across your team, and set up monitoring tools: sentry.auditware.io
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forefy
forefy@forefy·
🚨🚨 C4 SHUTS DOWN (and what does it mean) > since June last year @zellic_io did not take any profit to themselves for keeping @code4rena alive despite platform obvious costs > why? we can defer that Zellic's customers enjoyed the services there, and that its hell of a business lead-gen to be this middleman, even for free > bear market + AI submission spam is a bad combo, but even worse that it continues overtime without breathing air to many the OG stepping down might signal "contests are dead" (which was already the vibe with thedailywarden homepage) but to me it just says that it's a hard business running a contest platform nowadays if you're an auditor, don't use it as an excuse to give up - but take the lesson here that "easy" wins are no longer valuable - contests that pay need real criticals, real impact, hard research, niche focus areas and strengths its your time to shine ☀️ thanks @code4rena for reimagining crowdsourced security
Code4rena@code4rena

After careful consideration, we’ve made the decision to wind down @code4rena. This community has meant a great deal to everyone who has been part of building it, and sharing this news is not easy.

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