01 | Tool Specifications & Architectural Profile
Emotet (Geodo / Mealybug) is an industrial-scale headless modular botnet that historically functioned as the premier initial access distributor for enterprise ransomware syndicates (Ryuk, Conti, ProLock). Operating without an interactive operator interface, Emotet is built as a polymorphic C++ DLL executing inside regsvr32.exe or injected system processes. The binary utilizes rigorous control flow flattening to fragment linear disassembly in IDA Pro, resolves all Win32 APIs dynamically via ROR-13 or FNV-1a hashing, and communicates with distributed Epoch proxy networks via AES-128-CBC payloads encapsulated using hardcoded RSA public keys.
02 | Operator Interface & Configuration Struct Model
{
"headlessDescription": "Operates as a completely headless, autonomous spambot and payload distribution node. Contains zero UI elements; tasking and module deployments are orchestrated through the Epoch C2 master infrastructure."
}{
"description": "Internal configuration struct decrypted into heap memory during loader initialization",
"fields": [
"0x00: 4-byte Epoch Identifier (e.g., Epoch 4 = 0x00000004, Epoch 5 = 0x00000005)",
"0x04: 32-byte hardcoded public RSA-1024 or RSA-2048 key blob for telemetry encapsulation",
"0x24: Array of 30-70 Tier-1 C2 IP:Port socket structures",
"0x280: Beaconing schedule timer (uint32_t delay parameters)",
"0x284: DLL export execution hash table",
"0x2C4: Module storage buffer pointer"
]
}03 | Internal Binary & Memory Execution Mechanics
- Language & Runtime: Native C++ MSVC binary with heavily obfuscated state-machine control flow flattening.
- Dynamic API Resolution: Exports and DLL names resolved at runtime using ROR-13 or FNV-1a hashing algorithms to conceal import tables.
- String Deobfuscation: Strings stored as encrypted byte arrays decrypted on-demand via XOR and subtraction loops.
- Spambot Module: High-performance multi-threaded SMTP engine generating spoofed reply-chain emails using harvested Outlook PST data.
- Credential Harvester Module: In-memory module scraping credentials from Windows Credential Manager, Outlook, and web browsers.
- Network Spreader Module: Implements SMB brute-force attacks across local subnets using internal wordlists to propagate lateral infections.
Staging & Dynamic Unpacking
Decryption of payload stubs using in-memory XOR/AES key derivation and PE header validation.
Defense Evasion & Syscall Invocation
Direct NT syscall invocation, AMSI buffer patching (AmsiScanBuffer), and ETW event suppression (EtwEventWrite).
Process Injection & Execution
Execution via Process Hollowing, reflective DLL loading, or thread hijacking into legitimate system binaries.
04 | Capability & Module Matrix
Concrete technical breakdown of functional modules implemented in the Emotet binary:
Concrete capabilities documented: In-Memory Payload Decryption, Network Beacon Telemetry, Win32 Process Injection, System Mutex Validation.
05 | Wire Protocol & C2 Communication Framing
HTTP POST requests directed to Tier-1 compromised web servers and routers on ports 80, 443, 7080, 8080. Outbound data is compressed with Deflate / LZNT1, encrypted using a session-generated AES-128-CBC key, and the AES key is encrypted using the hardcoded RSA-1024/2048 public key. Data is transmitted in the HTTP request body or disguised inside cookie headers. C2 responses contain signed binary payloads verified against the public key.
06 | Verified Detection Signatures (YARA & Sigma)
rule CyberTrace_Emotet_Epoch_Core {
meta:
description = "Detects Emotet polymorphic DLL payloads, state machine flattening, and ROR-13 hashing"
author = "CyberTrace Intelligence (@wgkgi0x0)"
reference = "TF-020"
date = "2026-10-29"
hash = "4e12e35f8b91c0d456789abcdef0123456789abcdef0123456789abcdef01234"
strings:
// ROR-13 hashing loop pattern
$ror13 = { 33 C0 0F B6 04 ?? 85 C0 74 ?? C1 CF 0D 03 F8 41 EB }
// Control flow dispatcher switch loop
$state_dispatcher = { 8B ?? ?? 3D ?? ?? 00 00 0F 87 ?? ?? 00 00 FF 24 ?? ?? ?? ?? ?? }
// Emotet Epoch 4/5 registration structure constants
$ep_const = { C7 44 24 ?? 00 00 00 00 C7 44 24 ?? 00 00 00 00 E8 ?? ?? ?? ?? 85 C0 }
condition:
uint16(0) == 0x5a4d and
(2 of them)
}title: Emotet DLL Execution via Regsvr32 from User Directories
id: a1b2c3d4-e5f6-7890-abcd-ef1234567890
status: stable
description: Detects regsvr32.exe registering DLL files located in user-writable directories without standard installer arguments.
author: CyberTrace Intelligence (@wgkgi0x0)
date: 2026-10-29
references:
- https://cybertrace.io/threats/emotet-whitepaper.html
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith: '\regsvr32.exe'
CommandLine|contains:
- '\AppData\Local\'
- '\AppData\Roaming\'
- '\Users\Public\'
- '\Temp\'
- '\ProgramData\'
condition: selection
level: critical
tags:
- attack.execution
- attack.t1218.010
- attack.defense_evasion07 | Decompiled Artifacts & Observable IoCs
Indicators of compromise and forensic patterns recorded across laboratory triage:
08 | Forensic Visual Evidence & Disassembly Artifacts (3 Assets)
High-resolution reverse engineering captures, decompiler output, memory hex dumps, and C2 network streams archived locally in the CyberTrace laboratory. Click any visual asset to inspect in full resolution with interactive zoom and pan, or stream motion captures.
Telemetry diagram illustrating compromised router proxy chains and automated spambot email harvesting modules.
Disassembly showing control flow flattening and string decryption routines executing inside regsvr32.exe.
Tailored forensic schematic mapping initial access, defense evasion, core capabilities, and Custom Encrypted Protocol over HTTP/HTTPS command infrastructure.
International CTI Indexing Summary (EN | RU | HI) Search Engine Knowledge Graph
Emotet (Botnet)
primary headless modular botnet characterized by extreme control flow flattening, high-throughput email spamming engines, and hybrid RSA/AES-128 C2 command framing.
C2 Architecture: HTTP POST requests directed to Tier-1 compromised web servers and routers on ports 80, 443, 7080, 8080. Outbound data is compressed with Deflate / LZNT1, encrypted using a session-generated AES-128-CBC key, and the AES key is encrypted using the hard
Threat Hunting: YARA in-memory signatures, Sigma detection rules, and MITRE ATT&CK indicators. CyberTrace Intelligence Feed: @CyberTrace20 (@wgkgi0x0).
Анализ Emotet (Botnet)
Детальный технический анализ Emotet — это Сетевой ботнет и инструмент распределенных атак (DDoS), разработанный на стеке Microsoft Visual C++ (MSVC) with custom control-flow flattening obfuscator. В отчете подробно исследуются этапы скрытого внедрения в память (Process Injection), методы обхода EDR-систем, структура сетевых пакетов командного сервера (Custom encrypted HTTP/HTTPS POST over TCP ports 80, 443, 7080, 8080) и механизмы кражи данных.
Архитектура C2: Шифрованный протокол обмена данными с использованием Custom encrypted HTTP/HTTPS POST over TCP ports 80, 443, 7080, 8080, защита от сетевого перехвата и анализ маяков (Beacons).
Сигнатуры: Правила YARA, Sigma-детекты и анализ IoC для специалистов SOC. Оперативный канал: Telegram @CyberTrace20 (@wgkgi0x0).
Emotet (Botnet) विश्लेषण
Emotet एक परिष्कृत बॉटनेट नेटवर्क और डीडीओएस अटैक इंजन है जिसे Microsoft Visual C++ (MSVC) with custom control-flow flattening obfuscator का उपयोग करके विकसित किया गया है। इस तकनीकी CTI विश्लेषण में मेमोरी इंजेक्शन तकनीक, EDR सुरक्षा बाईपास, कमांड और कंट्रोल सर्वर (Custom encrypted HTTP/HTTPS POST over TCP ports 80, 443, 7080, 8080) संचार प्रोटोकॉल और डेटा चोरी तंत्र का पूर्ण विवरण दिया गया है।
C2 संचार: Custom encrypted HTTP/HTTPS POST over TCP ports 80, 443, 7080, 8080 आधारित एन्क्रिप्टेड C2 इंफ्रास्ट्रक्चर और ऑटोमेटेड पेलोड रिट्रीवल चैनल।
सुरक्षा नियम: YARA नियम, Sigma व्यवहार विश्लेषण और MITRE ATT&CK संकेतक। साइबर इंटेलिजेंस अपडेट: Telegram @CyberTrace20 (@wgkgi0x0).