Hijacking AI Agents, Part 2: Anatomy of a Hijack
A friendly git-helper skill hides a payload your Markdown preview never shows you. We take it apart line by line and watch one harmless request turn into four silent actions.
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Hijacking AI Agents, Part 1: The Trust Bug
Why your AI coding agent obeys strangers: the confused-deputy bug at the root of prompt injection, the trust tiers involved, and why the fix has to live outside the model.
Hiding in Plain Ledger: Four Months of a ClickFix Operator's Blockchain C2
To hide its command-and-control server, this operation writes the address onto a public blockchain. That makes the C2 impossible to seize or sinkhole — but it also means every time the operator moves servers, they leave a permanent, timestamped entry in a ledger anyone can read. I pulled that ledger. It runs to four months and roughly 127 delivery hosts from a single smart contract , and it was…
AnalystAIPack: Giving an AI Agent a Malware Analyst's Working Knowledge
AnalystAIPack is an open, Apache-2.0 library of runnable agent skills that give an AI agent a malware analyst's working knowledge across analysis, RE, and threat hunting.
Dead Drops on the Blockchain: Reversing a DPRK npm Loader (PolinRider / A6-Shadow-15)
We have all trained ourselves to look for the call home: the hard-coded IP, the suspicious .xyz domain, the base64 URL that decodes to something hostile. This loader has none of that. Strip it to nothing and you find an address on the TRON blockchain, which points to a Binance Smart Chain transaction sent to a burn address so it can never be spent or deleted. The next stage sits in that…
Peeling the Sandworm: Reversing the nhmpy PyPI Supply-Chain Worm (Shai-Hulud / Hades Wave)
The short version A package called nhmpy showed up on PyPI sitting one keystroke away from NumPy ( n-h-mpy instead of n-u-mpy ). It had already been pulled from the index and the wheel was far larger than NumPy has any reason to be, so I pulled the artifact apart to see what it was really doing. It turned out to be a credential stealer that goes to real trouble not to look like one. The package…
A new MuddyWater APT campaign spreads Backdoor RAT
MuddyWater is an APT group that has been active throughout 2017, targeting victims in the Middle East with in-memory vectors leveraging PowerShell. In October 2018, Kaspersky Lab published a good analysis report on the malware by this APT group. Here I am publishing my analysis report on recent malware by this APT group which targeted several parts of the Middle East. Sample -…
Flare-On Challenge 2018 Writeup
Flare-On is an annual CTF challenge organized by FireEye with a focus on reverse engineering. Overall, there were 12 challenges to complete, similar to last year (2017) . Instead of a detailed write-up, I am just covering the important parts. Following are the instructions to solve these challenges: Analyse the sample and find the key Each key looks like an email address and ends with…
Analysis of Noblis In-dev Ransomware
Noblis is in-development ransomware which is built in Python and packed by PyInstaller. You can refer to my previous blog to learn how to identify and reverse Python-built executables. We have the following sample: Hash : 3BEEE8D7F55CD8298FCB009AA6EF6AAE [ App.Any ] The sample is UPX packed; after unpacking we get the following sample. Hash : A886E7FAB4A2F1B1B048C217B4969762 The binary has many…
Analysis of File-Spider Ransomware
MD5: de7b31517d5963aefe70860d83ce83b9 [ VirusTotal ] FileName: BAYER_CROPSCIENCE_OFFICE_BEOGRAD_93876.doc FileType: MS Word Document The Word file has an embedded macro. When you look into the macro code, you will find the below snippet. Private Function decodeBase64(ByVal strData As String) As Byte() Dim objXML As MSXML2.DOMDocument Dim objNode As MSXML2.IXMLDOMElement Set objXML = New…
Analysis of LockCrypt ransomware
Introduction: Attackers have been recently breaking into corporate servers via RDP brute force attacks to spread a new variant of ransomware called LockCrypt. The attacks first started in June but there was an increase of attacks in October. The victims were asked to pay 0.5 to 1 BTC to recover their server. LockCrypt encrypts all files and renames them with a ‘.lock’ extension. It…
Flare-On Challenge 2017 Writeup
Flare-On is an annual CTF-style challenge organized by FireEye with a focus on reverse engineering. Overall, there were 12 challenges to complete. Instead of a detailed write-up, I am just covering the important parts. Following are the instructions to solve these challenges: Analyse the sample and find the key Each key looks like an email address and ends with @flare-on.com Enter the key for each…
Reverse Engineering of Python built executables
PyInstaller and py2exe bundle a Python application and all its dependencies into an executable file. The user can run the EXE file without installing a Python interpreter or any modules. As we all know, Python is an easy and effortless scripting language, so malware authors prefer Python for writing malware and convert it into an exe file using py2exe or PyInstaller. In this blog, I am going to…
Distributed processing using celery in python
Celery is an asynchronous task queue based on distributed message passing. Tasks are executed concurrently on one or more worker servers using multiprocessing, Eventlet or gevent. Tasks can execute asynchronously (in the background) or synchronously (wait until ready). Architecture: Fig1 : Celery architecture The main part of this architecture is the broker (transporter), which handles all the…
Analysis of Ransomware spread by JavaScript
Summary: The sample is a JavaScript file. After execution, it downloads a BAT file and an EXE file to run, traverses the computer’s files, and encrypts 80 kinds of file extensions including documents, pictures, media, etc. After the encryption, it asks for 0.5 BTC to decrypt the files. The malware author embeds malicious JavaScript in any kind of input data passed to an application that…
About
Melted in Hex is where threats get melted down to their raw bytes. I’m a malware analyst, reverse engineer, threat hunter, and AI security researcher. The instinct is the same one that’s always driven this work — take the thing apart, understand exactly how it operates, and figure out how to catch it — now pointed at a fast-changing, AI-driven attack surface, with AI in the loop. What…
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A filterable index of malware campaigns, ransomware families and APT operations analysed on Melted in Hex, with actor attribution, platform, ATT&CK mapping and detection coverage.