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ctf-malware Provides malware analysis and network traffic techniques for CTF challenges. Use when analyzing obfuscated scripts, malicious packages, custom crypto protocols, C2 traffic, PE/.NET binaries, RC4/AES encrypted communications, YARA rules, shellcode analysis, memory forensics for malware (Volatility malfind, process injection detection), anti-analysis techniques (VM/sandbox detection, timing evasion, API hashing, process injection, environment checks), or extracting malware configurations and indicators of compromise.
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Zipをダウンロード ダウンロード中... c2-and-protocols.md 10.5 KB scripts-and-obfuscation.md 15.4 KB category redteam name ctf-malware description Provides malware analysis and network traffic techniques for CTF challenges. Use when analyzing obfuscated scripts, malicious packages, custom crypto protocols, C2 traffic, PE/.NET binaries, RC4/AES encrypted communications, YARA rules, shellcode analysis, memory forensics for malware (Volatility malfind, process injection detection), anti-analysis techniques (VM/sandbox detection, timing evasion, API hashing, process injection, environment checks), or extracting malware configurations and indicators of compromise. license MIT compatibility Requires filesystem-based agent (Claude Code or similar) with bash, Python 3, and internet access for tool installation. allowed-tools Bash Read Write Edit Glob Grep Task WebFetch WebSearch metadata {"user-invocable":"false"}
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.
Prerequisites
Python packages (all platforms):
pip install yara-python pefile capstone oletools unicorn pycryptodome \
volatility3 dissect.cobaltstrike
Linux (apt):
apt install strace ltrace tshark binwalk binutils
macOS (Homebrew):
brew install wireshark binwalk binutils ghidra
Manual install:
dnSpy — GitHub , .NET decompiler (Windows)
Additional Resources
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), trojanized plugin analysis with custom alphabet C2 decodingc2-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 decryptionpe-and-dotnet.md - PE analysis (peframe, pe-sieve, pestudio), .NET analysis (dnSpy, AsmResolver), LimeRAT extraction, sandbox evasion, malware config extraction, PyInstaller+PyArmor
When to Pivot
If the sample is really just a normal crackme, packed challenge binary, or custom VM with no malware behavior, switch to /ctf-reverse.
If the main job is network reconstruction, disk carving, or host artifact recovery, switch to /ctf-forensics.
If the challenge turns into public attribution or infrastructure tracing, switch to /ctf-osint.
Quick Start Commands
head
head
"import pefile; pe=pefile.PE('mal.exe'); print(pe.dump_info())"
head
head
head
'[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
'http|ftp|ws://'
Obfuscated Scripts
Replace eval/bash with echo to print underlying code; extract base64/hex blobs and analyze with file. See scripts-and-obfuscation.md .
JavaScript & PowerShell Deobfuscation
JS: Replace eval with console.log, decode unescape(), atob(), String.fromCharCode().
PowerShell: Decode -enc base64, replace IEX with output. See scripts-and-obfuscation.md .
Junk Code Detection
NOP sleds, push/pop pairs, dead writes, unconditional jumps to next instruction. Filter to extract real call targets. See scripts-and-obfuscation.md .
PCAP & Network Analysis tshark -r file.pcap -Y "tcp.stream eq X" -T fields -e tcp.payload
Look for C2 on unusual ports. Extract IPs/domains with strings | grep. See c2-and-protocols.md .
Custom Crypto Protocols
Stream ciphers share keystream state for both directions; concatenate ALL payloads chronologically.
ChaCha20 keystream extraction: send nullbytes (0 XOR anything = anything). See c2-and-protocols.md .
C2 Traffic Patterns
Beaconing, DGA, DNS tunneling, HTTP(S) with custom headers, encoded payloads. See c2-and-protocols.md .
RC4-Encrypted WebSocket C2
Remap port with tcprewrite, add RSA key for TLS decryption, find RC4 key in binary. See c2-and-protocols.md .
Identifying Encryption Algorithms
AES: 0x637c777b S-box; ChaCha20: expand 32-byte k; TEA/XTEA: 0x9E3779B9; RC4: sequential S-box init. See c2-and-protocols.md .
AES-CBC in Malware
Key = MD5/SHA256 of hardcoded string; IV = first 16 bytes of ciphertext. See c2-and-protocols.md .
PE Analysis peframe malware.exe
pe-sieve
pestudio
.NET Malware Analysis
Use dnSpy/ILSpy for decompilation; AsmResolver for programmatic analysis. LimeRAT C2: AES-256-ECB with MD5-derived key. See pe-and-dotnet.md .
Malware Configuration Extraction
Check .data section, PE/.NET resources, registry keys, encrypted config files. See pe-and-dotnet.md .
Sandbox Evasion Checks
VM detection, debugger detection, timing checks, environment checks, analysis tool detection. See pe-and-dotnet.md .
Anti-Analysis Techniques VM detection (CPUID, MAC prefix, registry, disk size), timing evasion (sleep/RDTSC sandbox detection), API hashing (ROR13/DJB2/CRC32 + hashdb lookup), process injection (hollowing, APC, CreateRemoteThread), environment checks. See scripts-and-obfuscation.md .
Trojanized Plugin Analysis Diff malicious plugin against official release to find injected code in try/except blocks. Custom alphabet rotation (C[(C.index(ch) - offset) % len(C)]) decodes C2 domain, XOR decodes endpoint path. See scripts-and-obfuscation.md .
PyInstaller + PyArmor Unpacking
pyinstxtractor.py to extract, PyArmor-Unpacker for protected code. See pe-and-dotnet.md .
Telegram Bot Evidence Recovery
Use bot token from malware source to call getUpdates and getFile APIs. See c2-and-protocols.md .
Debian Package Analysis ar -x package.deb && tar -xf control.tar.xz
YARA Rules for Malware Detection Write YARA rules to match byte patterns, strings, and regex against files or memory dumps. Detect XOR loops ({31 ?? 80 ?? ?? 4? 75}), base64 blobs, encoded PowerShell. Use yarac to compile for faster scanning. See scripts-and-obfuscation.md .
Shellcode Analysis Disassemble with objdump -b binary -m i386:x86-64, emulate with Unicorn Engine (hook syscalls safely), or use Capstone for programmatic disassembly. Look for XOR decoder stubs. See scripts-and-obfuscation.md .
Memory Forensics for Malware vol3 windows.malfind detects injected code (PAGE_EXECUTE_READWRITE without mapped file). windows.pstree reveals suspicious parent-child relationships. YARA scan memory with yarascan.YaraScan. See scripts-and-obfuscation.md .
Network Indicators Quick Reference strings malware | grep -E '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
tshark -r capture.pcap -Y "dns.qry.name" -T fields -e dns.qry.name | sort -u
