Yehuda Smirnov (@yudasm_) profile picture

Security Researcher @Microsoft, opinions are my own.

Joined May 2022
Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)Photo by Yehuda Smirnov (@yudasm_)
Today @_rybaz and I are publicly releasing all the materials for our Introduction to Harness Engineering for Vulnerability Research training we gave at @unpromptedconf last week. Our goal was to teach the concepts we've been using to do much deeper security research and make both vulnerability analysis and red team engagements far more impactful. The workshop can be found here: grahamhelton.github.io/harne… The slides can be found here: grahamhelton.com/talks/2026-…
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Yehuda Smirnov retweeted
Bypassing SMB and LDAP signing with ntlmrelayx 🔥 I added both reauthentication bypasses to Impacket, now merged! Use –reauth-bypass on unpatched systems 🚀 LDAP can also start anonymously where accepted. Research: blackfield.ch/blog/defeating… and specterops.io/blog/2026/10/2…
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Yehuda Smirnov retweeted
Got this 2 days ago during a token replay attacks and... CAE policies bypass is working like a charm, no alerts nothing: mitiga.io/blog/hunting-condi… Then I had a look in the official documentation: such a gap in the coverage ! learn.microsoft.com/en-us/en… In short, at this stage, we are faced with the following situation: a blind SOC + policies that have been completely bypassed and no real solution until you increase your budget, ofc 👏
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Yehuda Smirnov retweeted
Video of my @UnpromptedAU & Bsides Canberra talks out now I built an autonomous N-Day exploit pipeline for the Windows kernel w/ mix of deterministic and AI-led stages. Results were comparable to what Anthropic achieved with Mythos using a much less powerful model.
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Yehuda Smirnov retweeted
LLMs are great at finding bugs, but so are fuzzers. @5aelo compared the vulnerabilities found in V8 by BigSleep, an agentic system, with those found by the Fuzzilli fuzzer. projectzero.google/2026/10/f…
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Yehuda Smirnov retweeted
Implemented SMB "reauth" from @aas_s3curity in my KreRelayEx tool too :-)
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Yehuda Smirnov retweeted
I wrote up a way to defeat enforced SMB signing for relay. It abuses a documented SMB re-authentication behavior. I'm surely missing nuance and prior art. Corrections welcome. Writeup: blackfield.ch/blog/defeating… PoC: github.com/aas-n/reauthx
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A quick article showing how the Jev OPSEC ranker works, and looking at how Jev can be used for identifying potentially sensitive file paths and content at speed.
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Yehuda Smirnov retweeted
Been digging deep into the Windows Endpoint Security Platform (WESP) in Win11 25H2, definitely one of the most fascinating security features Microsoft has built in a while. The concept is neat: compile rules to decision graphs in user mode, hand them to wesp.sys, and let the kernel evaluate them in-path while telemetry streams asynchronously in the background. I did an AI-assisted reverse engineering dive into the whole stack (wesp.sys, espclient.dll, and wesp_elam.sys), documented the wire protocols, disposition tables, and the enforcement gate, and built esptool, a research harness with 118 XML rule docs so anyone can test live telemetry and in-kernel blocking. Repo: github.com/marcosd4h/wesp_re… Tech doc: github.com/marcosd4h/wesp-re… Thanks to @yarden_shafir for putting this on my radar
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Yehuda Smirnov retweeted
My tweets haven't gone viral in a while now, so I must drop this banger: reburp And yes, it's a game changer in applicative pentest and bug bounty. Following me was worth it. Know how BurpSuite's API does not expose all that burpsuite can do in the UI? and how their MCP isn't better? it lets you read findings but can't do the workflows. reburp is a small burp extension that uses the extension's access to the internal Montoya API object to re-expose it over a localhost OpenAPI REST API to bridge all that a burp extension can do, to your AI agents in seconds ! Your agent can now use burp's: - active scan, stop/start scans, fuzzing, turbo intruder - iterate entire sitemap tree - websockets - use tools like Generate CSRF PoC - use other extensions e.g. Autorize - Create custom Bambda rules and custom scanners My favorite: you can explore burp features you haven't found in the UI even after 10 years using it github.com/forefy/reburp
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Yehuda Smirnov retweeted
Bypassing Android Hardware Attestation by Eric Le Guevel (@quarkslab) blog.quarkslab.com/bypassing… #infosec
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Yehuda Smirnov retweeted
Tracking OAuth token exchanges is complicated. TATS can help. @Icemoonhsv introduces the Token Analysis and Tracking System & shares some unexpected findings uncovered along the way. Check it out! ⤵️ ghst.ly/4xMBaYd
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Want to write kernel exploits or analyze malware? You need to understand Windows internals first. Syscalls, IRQL, pools, mitigations & more. Architecture 2821: Windows Kernel Internals 2 by Cedric Halbronn @saidelike ost2.fyi/Arch2821
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Yehuda Smirnov retweeted
The recording of "Deobfuscation in the Age of Agentic Reverse Engineering" is now public: youtube.com/watch?v=3-gJ6EUF… We (CC @nicolodev) show how to use agents to break protections found in anti-cheats, DRM systems & commercial protectors. Slides: synthesis.to/presentations/r…
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Yehuda Smirnov retweeted
There are numerous ways to extract cloud credentials (like tokens) once an attacker gains access to a workstation. Protect your cloud admin credentials as Tier 0. trustedsec.com/blog/securing…
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Yehuda Smirnov retweeted
Android 逆向最折腾的不是反编译 是反编译完以后 还得自己从一堆混淆代码里找接口 这个 android-reverse-engineering-skill 可以直接交给 Claude Code 做 把 APK,XAPK,JAR,AAR 丢进去 它会自动反编译,再把 Retrofit,OkHttp,Ktor,GraphQL 这些网络请求找出来 接口地址,认证方式,请求签名这些也能一起整理 碰到 R8 混淆 还能从 Kotlin metadata 里恢复一部分原始类名 继续顺着 Activity,ViewModel,Repository 往下追到真正的网络请求 平时做安全研究,协议分析 或者想快速看懂一个 Android App 怎么请求接口的 这个 Skill 可以装上 GitHub:github.com/SimoneAvogadro/an…
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