@_sigil

Senior Security Researcher @ Datadog. 🐕 Head in the (Azure) clouds. Sometimes blogging, always curious.

 Toronto, Ontario
kknowl.es
Joined September 2010
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149Media
♟️ What's an Agent ID compromise look like? This post shows how compromise of a blueprint can lead to compromise of ALL its agents, including those in another tenant: securitylabs.datadoghq.com/a…
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Thomas Naunheim@Thomas_LiveOct 6
🤖 New chapter: #AgentIdentities in the Attack & Defense Playbook for #MicrosoftEntra is live! 🔗 github.com/Cloud-Architekt/A… Together with @samilamppu, @RobbeVdDaele, and @DerkvanDerWoude, I’ve been researching #AgentID foundations, attack scenarios, detections, and mitigations.
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Hope Walker@IcemoonhsvSep 8
I've been teasing this project for a while in the Azure course and I am finally making my Token Analysis and Tracking System (TATS) public. Check out my latest blog to see more and share any cool things you find with TATS! specterops.io/blog/2026/09/0…

Token Analysis and Tracking System (TATS)

Tracking OAuth tokens is hard, but Token Analysis and Tracking System (TATS) can help. TATS will collect, store, decode, analyze and provide visual tracking for OAuth token exchanges. It was built to...

specterops.io
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🎸 Ever wondered how access packages change the privilege escalation model? I'll be presenting "Age of Entitlement: Breaking and Securing Entra Access Packages" at HIP Conf 26 in Nashville!! ➡️ Full lineup: semperis.swoogo.com/hipconf2… ➡️ Registration: semperis.swoogo.com/hipconf2…
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If you saw this on your computer screen, would you suspect it to be a malware-initiated passkey phishing attack? I will be presenting various deception techniques at #BHUSA next week. blackhat.com/us-26/briefings…
Passkey authentication prompt screenshot

ALT Passkey authentication prompt screenshot

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Highlighting this great writeup as I dig into Azure permissions this week. Access is more than just Azure RBAC and Entra roles: "'Who has access?' is not a one-query question in Azure. Permission lives in at least FIVE disjointed systems..."
Sysdig
@sysdigJul 15
🚨 One leaked credential. One morning. Full Azure tenant ownership. 03:27: First login. 03:29: Global Administrator. Self-granted. Two and a half minutes. No malware. No exploits. Just permissions. Full research from Sysdig TRT: okt.to/TKVDlu #CloudSecurity #ThreatResearch #Azure #IdentitySecurity
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Karl@kfosaaenJul 21
A new Azure VM command execution method dropping from @Thomasbyrne__ Technically a variation on the other Extension-based methods (Custom Script, DSC, etc.), but this one uses the Chef extension. Some really awesome work from Thomas on this one. netspi.com/blog/technical-bl…

Azure VM Command Execution using Third-Party Extensions - Chef

Discover how a privileged principal in Azure can abuse third-party extensions like Chef to achieve arbitrary command execution on target VMs by deploying malicious cookbooks to extract Managed...

netspi.com
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Merill Fernando
@merillJul 12
One compromised Agent ID blueprint can become a multitenant blast radius. @_sigil joined me to explain the trust boundary behind Microsoft Entra Agent ID and what admins should check before agent identities multiply. 🧵
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HIGHLY recommend @PentesterLab's Authentication & Authorization badge to get hands on with OAuth and SAML issues! Truly an eye-opening introduction: pentesterlab.com/badges/auth

PentesterLab: Learn with our Authentication / Authorization Badge

The Authentication/Authorization Badge covers vulnerabilities in authentication and authorisation. It focuses on SAML and Oauth.

pentesterlab.com
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🛡️Our final post on securing Entra Agent ID is up!! We'll cover how to protect, detect, and respond to an agent compromise in Entra: securitylabs.datadoghq.com/a… Thanks for joining us on the Agent ID series!
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Azeria
@Fox0x01Jul 4
Friendly reminder that the CFP for Unprompted is still open until July 31. If you’re working on something cool, submit! 😎
Unprompted AU@UnpromptedAUJun 24
We are excited to announce our first speaker for Unprompted.au: Valentina Palmiotti (@chompie1337), who will be presenting BinChomp - her autonomous n-day exploit generation pipeline!

[un]prompted.au — AI × Cybersecurity Conference · Sydney, 18–19 September 2026

Two days of original vulnerability research, exploit development, and frontier AI security at ILUMINA, Sydney. Explore the program.

unprompted.au
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Katie Knowles retweeted
Karl@kfosaaenJun 22
Some really nice work from @Thomasbyrne__ on the @NetSPI cloud team on a (now remediated) Entra CAP bypass - netspi.com/blog/technical-bl…

Bypassing Microsoft Entra Conditional Access Policies via Nested App Authentication

Discover how attackers bypassed Microsoft Entra Conditional Access Policies using Nested App Authentication (NAA) flows in this technical vulnerability breakdown.

netspi.com
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Nick Frichette
@Frichette_nJun 11
New research from @_sigil on Entra Agent ID! The first in a series, this time covering cross-tenant abuses. Follow the series at Datadog Security Labs. securitylabs.datadoghq.com/a…
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🤖 Entra Agent ID can have a larger blast radius than you think. Join us for a new series on all things agent identity! Check out part 1 on Agent ID fundamentals here: securitylabs.datadoghq.com/a…

Entra Agent ID: The blueprint blast radius

Entra Agent ID is an extension of Entra's application model that provides identities for AI agents. Unlike applications, the agent identity model allows linking a single app registration (blueprint)...

securitylabs.datadoghq.com
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Seeing new attributes pop-up is a strong signal that something is brewing in Entra ID. Ever wish this could be surfaced in an automated way? Enter changes.entra.ms - An automated system that scrapes #Entra for changes on a daily basis. #EntraID #infosec #mvpbuzz

Entra Change Tracker — Changelog

Automated monitoring of changes to the Microsoft Graph API, tracking Schema and Object changes across v1.0 and Beta endpoints.

changes.entra.ms
Jan Bakker@janbakker_29 Sep 2023
This is interesting.
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This BlueHat talk from Dylan Ryan-Zilavy and Cameron Vincent (@SecretlyHidden1) is an awesome watch! Fantastic bug and explanation of overlooked OAuth 'aud' claim validation: youtube.com/watch?v=oqq37nAt…

BlueHat 2026: Pulling strings: From user to global admin via appIdUris

In this talk, Cameron Vincent, Senior Security Researcher, Microsof...

youtube.com
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Nick Frichette
@Frichette_nMay 12
Malicious skills are evolving, and attackers are finding ways to execute them before model-level defenses even activate. In the first post of our new series, I’ll show you how dynamic context in coding agents can introduce new supply chain risks: securitylabs.datadoghq.com/a…

Malicious Coding Agent Skills and the Risk of Dynamic Context

Learn how malicious Claude Code skills can abuse dynamic context commands to execute before model-level prompt injection defenses can intervene.

securitylabs.datadoghq.com
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mdowd@mdowdMay 5
CFP is open!! Submit your cool talks about AI hacking/defense/core tech. Gonna be awesome!! ☺️
Unprompted AU@UnpromptedAUMay 5
The Unprompted.au CFP is officially OPEN! If you are doing cool stuff with AI in offense, defense, or working on core AI tech (from frontier models to open source LLMs), we'd love to hear from you! Submit here: unprompted.au/

[un]prompted.au — AI × Cybersecurity Conference · Sydney, 18–19 September 2026

Two days of original vulnerability research, exploit development, and frontier AI security at ILUMINA, Sydney. Explore the program.

unprompted.au
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mthcht@mthcht2Apr 29
Launching oauthsentry.github.io Look up any OAuth app ID and find out what it actually is across thousands of legitimate, risky, and malicious apps (Entra, Google, GitHub). Multiple feeds, API, detection ideas and remediation guidance. Still improving the detections a bit 🦾
oauthsentry.github.io

ALT oauthsentry.github.io

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🚨 Hey!! Have you checked out Stratus Red Team lately? We've been busy adding new techniques in Azure/Entra and GCP! Full lists below: GCP: stratus-red-team.cloud/attac… Azure: stratus-red-team.cloud/attac… Entra: stratus-red-team.cloud/attac…
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