Alex Ionescu

@aionescu · Montréal, Québec · joined 18 Apr 2008

Chief Technical Innovation Officer @crowdstrike. Windows Internals author and trainer. He/Him. RTs are not endorsements, opinions are my own.

48 084Followers

2 058Following

8 462Posts total

139.8KViews on collected posts

Derniers posts

Alex Ionescu@aionescu18 Aug

Great example of an exploit technique that HLAT (HVPT) mitigates. Since the IDT is protected by a RO VTL0 EPT, remapping the VA to different PA will result in an HLAT #EPF. 17K views · 119 likes · 25 reposts · 1 replies Open on X →

Alex Ionescu@aionescu4 Aug

When you forgot to tell Claude about C̵a̵l̵l̵b̵a̵c̵k̵ ̵O̵b̵j̵e̵c̵t̵s̵.̵ ̵W̵i̵n̵3̵2̵ ̵C̵a̵l̵l̵o̵u̵t̵s̵.̵ ̵E̵x̵t̵e̵n̵s̵i̵o̵n̵ ̵H̵o̵s̵t̵s̵.̵ ̵A̵P̵I̵ ̵S̵e̵t̵s̵.̵ Build a 8th mechanism to pass pointers between the kernel and Win32k.sys. https://t.co/Y9m4Z5IfCz

20.7K views · 205 likes · 11 reposts · 3 replies Open on X →

Alex Ionescu@aionescu18 Jul

I have literally two CVEs over the last decade with the same bug, in the same place, again, and again (and ten other researchers have ten more). It’s insane. When I still taught seminars I used to tell my classes “just scan memory for kernel pointers each build”. 20.9K views · 190 likes · 19 reposts · 6 replies Open on X →

Alex Ionescu@aionescu17 Jul

Wrote up CVE-2026-50416. win32k maps the desktop heap into every process. Offset 0x100 hands out a raw kernel session pool pointer. Readable from Low IL, AppContainer, even a zero capability LPAC. https://t.co/aiv6DOEc2I 37.4K views · 241 likes · 50 reposts · 3 replies Open on X →

Alex Ionescu@aionescu15 Jun

Very excited to see the talent we continue to bring together working on the next generation of our products. 6.1K views · 18 likes · 0 reposts · 1 replies Open on X →

Alex Ionescu@aionescu15 Jun

I'm thrilled to share that I am joining @CrowdStrike, along with a few of my colleagues I’ve most loved building with. When we founded @prequel_dev in 2023, we set out to change how teams find and fix security and reliability problems. Joining @CrowdStrike, a company I’ve long

8.7K views · 17 likes · 2 reposts · 2 replies Open on X →

Alex Ionescu@aionescu21 May

This information class was added only a few years ago. In the age of trillion dollar spending on AI code reviews and security, codeQL, KASAN and more, the world’s leading operating system kernel still added code to increment an arbitrary user controlled pointer in a system call 29.1K views · 99 likes · 14 reposts · 3 replies Open on X →

Face aux comptes de taille comparable

4 posts des 90 derniers jours, à côté de la tranche de 10K–100K abonnés. diffusé largement, mais peu de ces spectateurs réagissent.

Vues médianes20 768ce compte924médiane pour 10K–100K

Portée, %43.19%ce compte3.62%médiane pour 10K–100K

Engagement, %0.94%ce compte1.52%médiane pour 10K–100K

Indicateur	Ce compte	Médiane pour 10K–100K	Rapport
Vues médianes par post	20 768	924	22.5×
Portée (vues ÷ abonnés)	43.19%	3.62%	11.9×
Taux d'engagement	0.94%	1.52%	0.62×

Autres comptes de cette tranche → Comparer avec un autre compte → Comment ces repères sont établis →

Growth & engagement

How the posts we collected actually performed: views and reaction rate post by post, what the audience did with them, and where the follower count goes.

Views per post

29.1K21 May

8.7K15 Jun

6.1K

37.4K17 Jul

20.9K18 Jul

20.7K4 Aug

17K18 Aug

Last 7 collected posts, oldest on the left. The scale is logarithmic: one post can outrun the rest a hundred times over.

Engagement rate per post

0.40%21 May

0.24%15 Jun

0.31%

0.79%17 Jul

1.03%18 Jul

1.06%4 Aug

0.85%18 Aug

Reactions — likes, reposts, replies and quotes — divided by views. Median for 10K–100K accounts is 1.52%.

What the audience does

Likes62.9%889 in total

Reposts8.6%121 in total

Replies1.3%19 in total

Bookmarks27.2%385 in total

Share of every reaction we collected for this account. Replies mean argument, reposts mean endorsement, bookmarks mean the post was worth keeping.

The follower curve appears once this account has two daily snapshots — we take one a day, and this one is on its first.