Full Report
The operators of Vidar Stealer, one of the most successful malware-as-a-service (MaaS) operations of the past decade, have released a new major version to reflect massive improvements in the malware. [...]
Analysis Summary
# Tool/Technique: Vidar Stealer 2.0
## Overview
Vidar Stealer 2.0 is a major new version of the Vidar infostealer malware, rewritten in C to offer better performance, a smaller footprint, and enhanced capabilities for stealing sensitive user data from infected systems. Its primary purpose is the mass exfiltration of credentials, financial information, and account data from browsers and applications.
## Technical Details
- Type: Malware family (Infostealer)
- Platform: Windows (Inferred, as it targets Windows applications like Chrome)
- Capabilities: Multi-threaded data theft, extensive anti-analysis features, evasion of Chrome's App-Bound encryption, screenshot capture, collection of browser data, wallet data, and account credentials.
- First Seen: Announced by the developer in October 2025.
## MITRE ATT&CK Mapping
*Note: Specific detailed mappings are inferred based on the described techniques.*
- T1059 - Command and Scripting Interpreter (Implied by use of shellcode/DLL injection)
- T1059.003 - Windows Command Shell (Implied for execution context)
- T1027 - Obfuscated Files or Information
- T1027.002 - Code File Extension (Implied by polymorphism and control-flow flattening)
- T1055 - Process Injection
- T1055.001 - DLL Injection
- T1055.011 - Native API
- T1041 - Exfiltration Over C2 Channel (Implied by sending stolen data to delivery points)
## Functionality
### Core Capabilities
- **Data Theft**: Targets browser cookies, autofill data, cryptocurrency wallet extensions and desktop applications, cloud credentials, and data from Steam and Discord accounts.
- **Performance Optimization**: Rewritten completely in C (from C++) leading to fewer dependencies, smaller footprint, and better raw performance.
- **Parallel Collection**: Utilizes multi-thread CPU support to spawn worker threads simultaneously for data collection, aiming to reduce dwell time.
- **Data Packaging**: Captures screenshots of the infected machine, packages all stolen data, and prepares it for exfiltration.
### Advanced Features
- **Evasion (Anti-Analysis)**: Implements extensive anti-analysis checks including debugger detection, timing checks, uptime verification, and hardware profiling.
- **Polymorphism**: The builder offers polymorphism options utilizing heavy control-flow flattening and numeric state-machine switch constructs to complicate static analysis and detection.
- **Chrome App-Bound Encryption Bypass**: Bypasses Chrome's App-Bound encryption protection (a recent security feature) by:
1. Launching browsers with debugging enabled.
2. Injecting malicious code (shellcode or reflective DLL) directly into running browser processes.
3. Extracting encryption keys directly from browser memory space.
4. Communicating the stolen keys back to the main malware process via **named pipes** to avoid disk artifacts.
## Indicators of Compromise
- File Hashes: [Not specified in the article]
- File Names: [Not specified in the article]
- Registry Keys: [Not specified in the article]
- Network Indicators: Telegram bots, URLs stored on Steam profiles (Defanged example: `example-tg-bot` or `steam-profile-url-dot-com`)
- Behavioral Indicators: Spawning multiple CPU worker threads for data collection; use of named pipes for inter-process communication between the injected browser process and the main malware process; attempts to launch processes with debugging enabled.
## Associated Threat Actors
- [Not explicitly named, but associated with the developers selling the malware/builder.]
## Detection Methods
- Signature-based detection: Difficulty increased due to polymorphic builder features, control-flow flattening, and C rewrite.
- Behavioral detection: Detection should focus on the multi-threaded collection behavior, the use of named pipes for inter-process communication relating to credentials, and attempts to launch browsers/processes with debugging enabled (`CreateProcess` flags or process monitoring).
- YARA rules: [Not available in the article]
## Mitigation Strategies
- **System Hardening**: Ensure browsers are fully updated to benefit from security patches, although this technique is focused on bypassing current implementations.
- **Endpoint Security**: Utilize EDR/XDR solutions capable of detecting memory injection techniques (shellcode or reflective DLL loading) into critical processes like browsers.
- **Principle of Least Privilege**: Limit user permissions to restrict the malware's ability to execute arbitrary code or manipulate system settings.
- **Network Monitoring**: Monitor for outbound connections to known exfiltration vectors such as Telegram APIs or unconventional C2 infrastructure (like Steam profiles).
## Related Tools/Techniques
- Lumma Stealer (Competitor whose decline positions Vidar 2.0 for market share)
- Other infostealers that have bypassed Chrome's App-Bound encryption (e.g., other malware families mentioned in the article as having also bypassed the feature).