debugging-malware-with-x64dbg

debugging-malware-with-x64dbg is a skill for Claude Code, Codex from meltedinhex/analyst-ai-pack. It costs 75 tokens per session (916 once invoked), scanned A, original, Apache-2.0.

A hands-on guide for using x64dbg, a Windows program debugger, to observe malware while it runs. It focuses on strategic breakpoints, unpacking and decryption, memory dumps, and bypassing analysis barriers.

In plain words
What is it for?
Use it to investigate unpacking, decrypted strings, process hollowing, and injection behavior in an isolated Windows virtual machine. The sample executes during analysis, so a disposable lab and clean snapshot are required.
Why use it?
Malware often hides its real code until execution, so static inspection alone may not reveal its behavior. Debugging lets an analyst stop at key Windows operations and inspect the decoded payload.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to investigate unpacking, decrypted strings, process hollowing, and injection behavior in an isolated Windows virtual machine. The sample executes during analysis, so a disposable lab and clean snapshot are required.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/meltedinhex/analyst-ai-pack/debugging-malware-with-x64dbg
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add meltedinhex/analyst-ai-pack --skill debugging-malware-with-x64dbg
Clone the repo
git clone --depth 1 https://github.com/meltedinhex/analyst-ai-pack

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for debugging-malware-with-x64dbg

README.md
[![agentmods](https://agentmods.dev/badge/skills/meltedinhex/analyst-ai-pack/debugging-malware-with-x64dbg.svg)](https://agentmods.dev/skills/meltedinhex/analyst-ai-pack/debugging-malware-with-x64dbg)
Your own site
<a href="https://agentmods.dev/skills/meltedinhex/analyst-ai-pack/debugging-malware-with-x64dbg"><img src="https://agentmods.dev/badge/skills/meltedinhex/analyst-ai-pack/debugging-malware-with-x64dbg.svg" alt="Measured on agentmods" height="20"></a>
Per session 75 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 916 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00075 $0.00916
Opus 5 $0.00037 $0.00458
Sonnet 5 $0.00015 $0.00183
Haiku 4.5 $0.00007 $0.00092

Measured 8d ago against content hash e2c8ff91c78c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

debugging-malware-with-x64dbg scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/analyst.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/debugging-malware-with-x64dbg/SKILL.md · 112 lines

How it starts

The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugging Malware with x64dbg

When to Use

  • You need to observe a sample's runtime behavior at the instruction level on Windows.
  • You are manually unpacking, decrypting strings, or reaching code guarded by anti-analysis.
  • You want to dump a payload from memory after it is decoded but before it is hidden.

Do not use a debugger on a host you care about — debug only inside the isolated victim VM, and revert the snapshot after.

Prerequisites

  • x64dbg (and the matching x32/x64 build for the sample's bitness) inside the victim VM.
  • A clean snapshot; the lab's simulated internet.
  • Familiarity with Windows APIs commonly used by malware.

Safety & Handling

  • The sample executes under the debugger; this is detonation. Stay in the isolated VM.
  • Revert the snapshot after the session; treat memory dumps as live samples.

Workflow

Step 1: Set strategic API breakpoints

Rather than stepping from the entry point, break on APIs that mark interesting moments:

VirtualAlloc / VirtualProtect  -> unpacking buffer about to be written/executed
CreateProcessInternalW         -> process hollowing target
WriteProcessMemory             -> injection payload in a register/buffer
CryptDecrypt / lstrcpy         -> decoded data available
ResumeThread                   -> hollowed process about to run

Use bp VirtualAlloc then inspect the return value (allocated base) on return.

Step 2: Step through unpacking

Run to the allocation, set a memory breakpoint on the new region, and continue until the unpacker writes and jumps to it. The tail jump to OEP marks the unpacked entry.

Step 3: Dump at the right moment

When the payload is decoded in memory (e.g. after VirtualProtect makes it executable), dump the region with Scylla/the dump plugin and fix the import table for the unpacked PE.

Step 4: Defeat simple anti-debugging

Patch or skip checks like IsDebuggerPresent, PEB BeingDebugged, and timing checks (see the anti-debugging skill). Set the return value to evade detection rather than removing the call.

Read the full file on GitHub · 112 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 112 lines · 75 tokens per session scan A e2c8ff91c78c

Subscribe to this mod's changes

debugging-malware-with-x64dbg is a skill published in the GitHub repository meltedinhex/analyst-ai-pack (22 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 75 tokens to every session and 916 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

analyzing-golang-malware-with-ghidra

Reverse engineer Go-compiled malware in Ghidra by parsing Go buildinfo and pclntab structures, recovering stripped/obfuscated function names (e.g. via GoResolver), and extracting embedded module/dependency strings and types from Go binaries. Use when analyzing a Go-language malware sample, deobfuscating a…

mukul975/Anthropic-Cybersecurity-Skills · 95 tokens

analyzing-malware-persistence-with-autoruns

Use Sysinternals Autoruns to systematically enumerate and analyze malware persistence mechanisms across Windows registry run keys, scheduled tasks, services, drivers, and startup locations. Use when hunting for persistence during Windows incident response, triaging a compromised endpoint, or validating that malware…

mukul975/Anthropic-Cybersecurity-Skills · 74 tokens

analyzing-malicious-pdf-with-peepdf

Perform static analysis of malicious PDF documents using peepdf, pdfid, and pdf-parser to extract embedded JavaScript, shellcode, and suspicious objects. Use when triaging a suspicious PDF attachment from a phishing email, analyzing a PDF-based exploit document, or building detection signatures for weaponized PDF…

mukul975/Anthropic-Cybersecurity-Skills · 73 tokens

analyzing-malware-persistence-with-autoruns

Use Sysinternals Autoruns to systematically identify and analyze malware persistence mechanisms across registry keys, scheduled tasks, services, drivers, and startup locations on Windows systems.

plurigrid/asi · 44 tokens

analyzing-malicious-pdf-with-peepdf

A Chinese-language skill for examining suspicious PDF files with peepdf, pdfid, and pdf-parser. It is intended for static malware analysis, which studies a file without running it.

killvxk/cybersecurity-skills-zh · 50 tokens

analyzing-malicious-pdf-with-peepdf

Perform static analysis of malicious PDF documents using peepdf, pdfid, and pdf-parser to extract embedded JavaScript, shellcode, and suspicious objects.

26zl/cybersec-toolkit · 43 tokens