COSMO STEALER 2025

The evolution of information stealers has reached new heights in 2025, with modern variants demonstrating unprecedented sophistication in data harvesting and evasion techniques. Among these threats, a particularly advanced strain has emerged as a favorite of cybercriminals due to its modular design, broad targeting capabilities, and robust anti-detection mechanisms. COSMO STEALER 2025 exemplifies the current trend of “as-a-service” cybercrime tools, where malicious software is rented or sold to less technically skilled attackers, significantly lowering the barrier to entry for conducting damaging cyber operations. Its prevalence in credential theft, financial fraud, and corporate espionage campaigns makes it a critical threat to both individual and organizational security.

This stealer malware is a comprehensive data harvesting tool designed to extract sensitive information from infected systems with surgical precision. It primarily targets authentication credentials, financial data, cryptocurrency wallets, and system information that can be leveraged for further attacks. Distributed through phishing campaigns, malvertising, and compromised software downloads, it’s commonly used in identity theft operations, banking fraud, and as an initial access vector for ransomware groups. The malware’s ability to bypass multi-factor authentication through session cookie theft makes it especially dangerous in today’s security landscape.

Key Features

Feature	Description
Credential Harvesting	Extracts saved logins from 80+ browsers and password managers
Session Hijacking	Steals authentication cookies to bypass MFA
Cryptocurrency Theft	Targets 30+ wallet applications and clipboard crypto addresses
Form Grabbing	Captures form submissions in real-time across applications
File Exfiltration	Searches for and uploads specific document types (PDF, DOCX, etc.)
System Fingerprinting	Collects detailed hardware/software profiles for targeted attacks
Evasion Suite	Incorporates 10+ anti-analysis techniques, including VM/sandbox detection
Modular Architecture	Allows runtime loading of additional malicious plugins

How COSMO STEALER 2025 Works

Infection and Initial Execution

The malware employs multiple sophisticated delivery mechanisms:

Polymorphic Loaders: Each infection uses unique, randomly generated code to evade signature detection
Fileless Techniques: Direct memory injection, avoiding disk writes when possible
Legitimate Process Abuse: Leverages trusted system processes like msiexec.exe for execution

Upon activation, the malware performs:

Environment Analysis: Checks for security tools, analysis environments, or corporate networks
Persistence Establishment: Creates scheduled tasks or registry entries for long-term access
Privilege Escalation: Exploits known local vulnerabilities to gain higher permissions

Data Collection Process

The stealer operates through multiple parallel collection modules:

Browser Data Extraction:
- Decrypts and exports saved credentials from Chromium and Firefox-based browsers
- Harvests autofill data, including names, addresses, and payment information
- Extracts session cookies with special attention to cloud services (Office 365, AWS, etc.)
System Reconnaissance:
- Collects installed software lists with versions for vulnerability targeting
- Gathers network configuration data, including connected devices
- Screenshots of active desktop sessions
Financial Data Targeting:
- Scans for cryptocurrency wallet files (Electrum, Exodus, MetaMask, etc.)
- Monitors the clipboard for cryptocurrency address patterns
- Extracts credit card information from browser storage and autofill databases

Advanced Evasion Techniques

The malware incorporates cutting-edge anti-detection methods:

API Unhooking: Bypasses security product monitoring of system calls
Time-Based Triggers: Delays malicious activity until specific times or events
Process Hollowing: Executes malicious code within legitimate process memory space
Garbage Code Injection: Fills memory with meaningless data to hinder analysis

Data Processing and Exfiltration

Collected information undergoes sophisticated handling:

Data Structuring: Organizes stolen data by type and priority
Compression: Uses custom algorithms to minimize size
Encryption: Applies multiple layers of encryption, including RSA and AES
Exfiltration: Transmits via:
- HTTPS to cloud storage providers
- Telegram bot API as a fallback
- DNS tunneling in restricted environments

Command and Control Infrastructure

The malware uses a resilient C2 architecture:

Domain Generation Algorithm (DGA): Creates hundreds of potential C2 domains daily
Blockchain-Based C2: Leverages cryptocurrency transactions for stealthy communication
Peer-to-Peer Fallback: Can use infected hosts as relays if the primary C2 is unavailable