# Ctf Malware

> CTF Malware & Network Analysis

- Skill: `mateobogo/ctf-malware` (Agent Skill, multi-file: 5 files)
- Install (CLI): `npx skillmds@latest add mateobogo/ctf-malware`
- Raw SKILL.md: https://api.skillmd.com/api/skills/mateobogo/ctf-malware/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: MateoBogo (https://skillmd.com/u/mateobogo)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/mateobogo/ctf-malware

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# CTF Malware & Network Analysis

Quick reference for malware analysis CTF challenges. Each technique has a one-liner here; see supporting files for full details with code.

## Additional Resources

- [scripts-and-obfuscation.md](scripts-and-obfuscation.md) - JavaScript deobfuscation, PowerShell analysis, eval/base64 decoding, junk code detection, hex payloads, Debian package analysis, dynamic analysis techniques (strace/ltrace, network monitoring, memory string extraction, automated sandbox execution), YARA rules for malware detection, shellcode analysis (Unicorn Engine, Capstone), memory forensics for malware (Volatility 3 malfind, process injection detection), anti-analysis techniques (VM detection, timing evasion, API hashing, process injection)
- [c2-and-protocols.md](c2-and-protocols.md) - C2 traffic patterns, custom crypto protocols, RC4 WebSocket, DNS-based C2, network indicators, PCAP analysis, AES-CBC, encryption ID, Telegram bot recovery, Poison Ivy RAT Camellia decryption
- [pe-and-dotnet.md](pe-and-dotnet.md) - PE analysis (peframe, pe-sieve, pestudio), .NET analysis (dnSpy, AsmResolver), LimeRAT extraction, sandbox evasion, malware config extraction, PyInstaller+PyArmor

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## Pattern Recognition Index

Dispatch on **byte/file signals**, never the sample's reputation.

| Signal | Technique → file |
|---|---|
| File starts with `PK` + contains `package.json` + `.vsix` extension | VSCode extension activation-event exfil → scripts-and-obfuscation.md |
| High-entropy `extension.js`/`index.js` > 50 KB with `child_process` | JS obfuscator.io / JSFuck deobfuscation → scripts-and-obfuscation.md |
| PowerShell `-enc <b64>` or IEX in parent process logs | PS script decode + reflection assembly → scripts-and-obfuscation.md |
| PCAP with custom TCP port, payload bytes distributed uniformly | Custom crypto / RC4 / AES session key recovery → c2-and-protocols.md |
| PCAP with `DNS TXT` records carrying base32/64 blobs | DNS-based C2 exfil → c2-and-protocols.md |
| PCAP where specific User-Agent receives non-default responses | UA-gated C2 path-hex-XOR → (see ctf-forensics/network-advanced.md) |
| PE32/PE64 with `.text` sections having packer signatures (UPX, VMProtect, Themida) | Unpacking + dump-after-decrypt → pe-and-dotnet.md |
| .NET assembly with obfuscated strings + reflection calls | dnSpy + de4dot + string decryption → pe-and-dotnet.md |
| PyInstaller binary (`MEIPASS`, `_MEIxxxx` strings) | pyinstxtractor + pycdc → pe-and-dotnet.md |
| Process-injection IoCs in memory dump (`RWX` allocations, `NtUnmapViewOfSection`) | Volatility `malfind` + process hollowing detection → scripts-and-obfuscation.md |
| Anti-VM checks (`cpuid` hypervisor bit, RDTSC timing, specific drivers) | VM-detection bypass in analysis sandbox → scripts-and-obfuscation.md |
| WebSocket frame with visible RC4 key-setup or KSA signatures | RC4 WebSocket reversing → c2-and-protocols.md |

Recognize the **artefact or protocol pattern**. The sample's name is not a signal.

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For inline snippets and quick-reference tables, see [quickref.md](quickref.md). The Pattern Recognition Index above is the dispatch table — always consult it first.