Dray Agha Profile picture
Feb 7, 2022 8 tweets 4 min read Read on X
This is awesome, thank you @x86matthew.

I wanted to share a blue team perspective on monitoring and hunting for this kind of LNK -> EXE bamboozling

We'll use the example PoC if that's alright with you 🧵
Let's execute the PoC of the .LNK, which brings a pop up.

@x86matthew was kind enough to create a non-malicious PoC. But of course an adversary will not be so kind.

So let's take a look at our logs: Image
Let's assume we're rolling with SysMon.

We get an Event 11 for a strange tmp*.exe being created. This of course could be called something different if re-engineered by an adversary IRL.

But for now let's focus on this tmp*.exe Image
We can see a process is connected to this tmp*.exe, with a parent PowerShell process offering us some insight into the tmp*.exe. Image
We can then find evidence that the .LNK was successful in executing.

Not just because we received the pop up box, but because in our Prefetch directory we can see evidence of the tmp*.exe successfully executing Image
Okay so that's a post-mortem of monitoring execution.

Your logging / SIEM solutions aren't blind to this technique, but it is not immediately obvious that it originated from LNK to EXE

Now, I want to talk about how to proactively HUNT for this🕵️🔍🔍
This PwSh one-liner asks for LNKs, and specifies 'only show me after X date'. Then, it asks to see the filename and the related target.

This PwSh is noisy if you don't filter well! But shows anomalies, and scales well for a tool like Velociraptor. Image
Probably missed loads here, but wanted to contribute with some defence insights.

Thanks @x86matthew

If anyone wants the above PowerShell, or other blue team tips, I have them on my repo: github.com/Purp1eW0lf/Blu…

End of thread 🧵

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More from @Purp1eW0lf

Dec 5, 2022
Think hiring is slowing down??

@HuntressLabs is hiring remote a Threat Operations Analyst 🇬🇧. UK citizenship is non-negotiable

You'll be working with myself, @xorJosh, @PonchoSec, and the rest of the squad!

I have some tips for those applying 🧵

boards.greenhouse.io/huntress/jobs/…
I don't care about about degrees 📜

I barely care about certs.

I care about what your contributions have been to your community.

Do you have a github, a blog, a summary of a CTF you did ? GREAT, put the link in your resume
We're gonna teach you what you need to know in this role👨‍🎓

But I need to know from your resume, covering letter, and interview that you take extreme ownership and accountability for yourself.

Meaning, you're constantly learning and trying to execute high quality, accurate work
Read 7 tweets
Oct 11, 2022
For cyber security investigations, internal silos will make or break your efforts 🧱🧱🧱

I'll show you the power from a LACK of siloing, with a piping hot, fresh @HuntressLabs case @xorJosh and I worked

🧵🧶
What are 'silos'.

@keydet89 educated me on the industry problem where departments cannot easily share findings; a threat intel department doesn't have a way to share findings with DFIR department, for example.

IMO, Silos occur when data & people cannot be circulated easily
We aren't perfect by any means at @HuntressLabs, but it's a testament to our founders, engineers, devs (etc) that our infrastructure sets us up for success.

It's difficult for analysts NOT to share reports and data by default; our infrastructure & culture doesn't foster silos
Read 15 tweets
Sep 29, 2022
Investigating an intrusion? 🕵️🔍

Start with the security solution on the machine. DON'T work hard to timeline the adversaries' activities, work smart👩‍🔬

In a @HuntressLabs case with @nosecurething and Jordan Sexton, we leveraged ESET's data before anything forensically complex🧵 Image
This gave us a tonne of starter info
🟡 Timestamps threat actor operated in

🔴 Directories they liked to operate in, the user account they likely controlled, AND that the threat actor liked to use PwSh

🔵 Registry key they had used for persistence.

This saved us time....⏲️
..as we used these findings to pivot:

🟡 We had date/time anchor points when leveraging other data

🔴 We focused on the user, those directories, and PwSh. Found more malicious activity straight away

🔵 We eradicated persistence and identified their IPv4: 5[.]255[.]103[.]142 ImageImageImage
Read 5 tweets
Sep 8, 2022
I wanted to share some findings about RDP, Network Layer Authentication, LogonTypes and brute forcing 🔭

Recently, we perused some EventID 4625s (login failures) originating from public IPv4s brute forcing...
🧵
I kept finding LogonType 3s (network)

However only RDP was externally exposed on the machine, which usually records LogonType 10....

When this has happened before, I usually just assume its Windows jank and continue with my investigation 🤷‍♂️

But this time, I wanted to know WHY
The wise @DaveKleinatland suggested Network Layer Authentication (NLA) would explain this:

"
NLA takes place before the session is started... without NLA things can be exposed before any sort of authentication.... like domain name, usernames, last logged on user, etc
"
- Dave 🧙‍♂️
Read 10 tweets
Aug 17, 2022
In a recent intrusion, we identified a threat actor had compromised the Windows login process, and siphoned cleartext credentials - using a technique known as NPPSPY

@0gtweet’s NPPSPY was fascinating to dissect and remediate.

Huge thanks to @keydet89 for guidance and wisdom
Our article couldn’t show what this cleartext credential gathering looked like on the compromised machine, but we recreated the electrifying end product
IOCs and Behavior
- T1003

- Values under HKLM\SYSTEM\CurrentControlSet\Control\NetworkProvider\Order
◦For our case: logincontroll

- Unexplained entries in HKLM\SYSTEM\CurrentControlSet\Services\<here>\NetworkProvider
◦For our case: logincontroll
Read 5 tweets
Aug 16, 2022
Cobalt Strike ain't 💩

Let's chat about how to unravel Cobalt Strike and deny the adversary further access

As ALWAYS, I am showing you data so fresh out the kitchen it hasn't even been cleared by ThreatOps Director @MaxRogers5 👀🧑‍🍳 🧵
Cobalt Strike can often trigger AMSI alerts in Defender. The frustrating thing about AMSI alerts is that they don't tell you what the offending activity WAS.

The alert here was PowerShell based....so let's dig a lil deeper
Go collect C:\System32\winevt\Logs\Microsoft-Windows-PowerShell%4Operational.evtx , and go get my favourite tool - Chainsaw.

Take note your detection time (06:43).

Point chainsaw at your PwSh log, with this time
Read 13 tweets

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