Principal Identity Security Researcher at Microsoft. Ex-Secureworks. (MSc, MEng, PhD, CITP, CCSK). And yes, opinions are my own ;)
Tampere, Finland
- Tweets 5,772
- Following 1,791
- Followers 21,132
- Likes 14,123
Pinned Tweet
#AADInternals Azure AD & Microsoft 365 kill chain shows how different attacker roles can get access to #AzureAD and #Microsoft365.
Pro tips:
1. Use MFA!
2. Avoid inviting unnecessary guests
3. Minimize # of Global Admins
4. Protect your on-prem servers
o365blog.com/aadkillchain/
6
178
560
Good Morning London 🇬🇧!
Traditional morning run in Hyde Park 🏃♂️ barely avoiding Storm Austen ⛈️
16
855
Big news from the work front: I've decided to leave @Microsoft!
My last working day is October 31 (remaining employed through January). Looking back, my journey to the dark side lasted a little over three years.
Huge thanks to @JohnLaTwC, @TimbMsft, Elia Florio and the team, it’s been a fantastic ride! I’ll also miss working with the @msftsecresponse folks, although I have no doubt our paths will cross again 😉
What's next? Stay tuned!
20
212
10,998
Dr. Nestori Syynimaa retweeted
Did you know that if you have Entra ID P1 there is a new way to block your stolen refresh token from being replayed by the attacker?
Find out 🧵👇
1/7
13
49
255
26,021
👀
He copied a value out of the Windows Event Log.
Pasted it into his special browser.
And he was signed into Microsoft Entra as the user who had just authenticated.
No password. No phishing link. No stolen private key.
@MGrafnetter's Black Hat USA 2026 research...
1
2
20
5,938
Dr. Nestori Syynimaa retweeted
Four years of planning the shots paid off.
#EclipseEspaña #Eclipse
463
18,019
179,164
2,331,013
RT @Enno_Insinuator: Black Hat US 2026 with a bunch of researchers of the @ERNW_ITSec “Education Team”
2
171
Dr. Nestori Syynimaa retweeted
A record-breaking year for Microsoft's Bounty Programs!
This year, Microsoft awarded more than $20 million to 562 security researchers, the highest total payout and largest number of researchers recognized in program history.
Read the full blog to learn more about the impact of the global security research community: aka.ms/microsoft-bounty-year…
Made with AI
3
14
61
7,735
Dr. Nestori Syynimaa retweeted
For those that missed it the Active Directory tier model documentation recently had a huge uplift, and even more importantly, the scripts used to configure your AD in line with this tiered model (tier 0-1-2) have been fully open sourced for your use.
The updated repo also contains scripts to audit drift from the baselines, and a detailed FAQ to help you deploy the model.
github.com/microsoft/ActiveD…
2
103
478
26,137
Adhoc trip to Copenhagen 🇩🇰 with @SuviSyynimaa day 1 ended with visit to Tivoli 🥂🎡
1
11
1,505
Dr. Nestori Syynimaa retweeted
#TROOPERS26 videos published:
piped.video/playlist?list=PL…
21
48
10,626
Dr. Nestori Syynimaa retweeted
⏰ Final reminder: Registration for BlueHat Asia closes tonight at 11:59 PM. Secure your spot before registration closes: aka.ms/bluehatreg
BlueHat Asia is heading to Singapore on September 17–18!
👉Apply now for your chance to join us: aka.ms/bluehatreg
Applications close July 17.
#BlueHat
3
20
8,129