Full Report
Defenders have observed CoffeeLoader, a new stealthy malware that evades security protection using advanced evasion techniques and takes advantage of Red Team methods to boost its effectiveness. Distributed via SmokeLoader, CoffeeLoader implements secondary payloads while evading detection, making its stealthy attacks challenging to detect and defend against. Detect CoffeeLoader With more than 1 billion malware […] The post CoffeeLoader Detection: A New Sophisticated Malware Family Spread via SmokeLoader appeared first on SOC Prime.
Analysis Summary
# Tool/Technique: CoffeeLoader
## Overview
CoffeeLoader is a new, stealthy malware family characterized by advanced evasion techniques designed to bypass Anti-Virus (AV), Endpoint Detection and Response (EDR), and sandbox environments. It utilizes innovative techniques, some shared with SmokeLoader, to enhance its offensive capabilities.
## Technical Details
- Type: Malware family
- Platform: Windows (Inferred from behavior like scheduled tasks, Windows APIs, and association with SmokeLoader)
- Capabilities: Advanced evasion techniques against AV/EDR/sandboxes, process injection via a stager, bot ID generation, mutex creation, import hashing, encryption of network traffic (RC4), use of low-level Windows APIs, setting file attributes to system/hidden, and persistence via scheduled tasks.
- First Seen: Recently observed, with context suggesting observation around March 2025.
## MITRE ATT&CK Mapping
The description strongly implies coverage of the following general tactics and techniques based on stated capabilities:
- **TA0005 - Defense Evasion**
- T1027 - Obfuscated Files or Information (Inferred from advanced evasion techniques)
- T1055 - Process Injection
- **TA0003 - Persistence**
- T1547.001 - Registry Run Keys / Startup Folder (Implied by persistence methodology, though scheduled tasks are explicitly mentioned)
- T1053.005 - Scheduled Task/Job
- **TA0011 - Command and Control**
- T1071.001 - Application Layer Protocol (Implied by network traffic usage, though specific protocol isn't detailed)
## Functionality
### Core Capabilities
- **Evasion:** Designed specifically to bypass modern security controls including AVs, EDRs, and sandboxes.
- **Infection Chain:** Uses a stager mechanism to inject a main malicious module into another running process.
- **Identification:** Generates a unique Bot ID based on system identifiers.
- **System Integration:** Creates a mutex tied explicitly to its generated Bot ID.
- **Execution Environment:** Sets file attributes to 'system' and 'hidden' to blend in.
### Advanced Features
- **Import Resolution:** Resolves necessary API imports by calculating their hash, obscuring standard import tables.
- **Internal Structure:** Relies on a global data structure to manage internal variables and pointers for API functions.
- **Network Obfuscation:** Encrypts outbound network communications using hardcoded RC4 keys.
- **API Usage:** Heavily utilizes low-level Windows system APIs to reduce observability from higher-level security hooks.
- **Persistence:** Maintains persistence through the creation of Scheduled Tasks.
## Indicators of Compromise
*Note: Specific IoCs (hashes, IPs) were not provided in the abstract, but behavioral indicators are listed based on functionality.*
- File Hashes: [Not specified in context]
- File Names: [Not specified in context]
- Registry Keys: [Not specified in context]
- Network Indicators: Network traffic is encrypted using RC4. [No specific C2 domains/IPs provided, defanged context is irrelevant as none were listed.]
- Behavioral Indicators:
- Injection of code into a legitimate process.
- Creation of system/hidden file attributes.
- Creation of a scheduled task for persistence.
- Creation of an ID-specific mutex.
- Use of resolving imports via hash calculation.
## Associated Threat Actors
The documentation notes significant overlap with the **SmokeLoader** malware family, suggesting potential operators of SmokeLoader or groups leveraging similar development techniques. The article mentions SmokeLoader's use in attacks against Ukraine.
## Detection Methods
Since CoffeeLoader focuses heavily on advanced evasion, detection requires non-signature-based analysis:
- Signature-based detection: Likely low effectiveness due to obfuscation and dynamic resolution.
- Behavioral detection: Critical for detecting process-injection sequences, low-level API calls, and unexpected scheduled task creation.
- YARA rules: Requires rules targeting the specific internal structures, import hashing mechanism, or the RC4 routines.
## Mitigation Strategies
- Prevention measures: Robust application control, least privilege enforcement.
- Hardening recommendations: Monitoring for process injection targeting legitimate processes, scrutinizing new scheduled task creation, and monitoring for file attribute changes to 'hidden'/'system'.
## Related Tools/Techniques
- **SmokeLoader**: Shares significant capabilities with CoffeeLoader, suggesting a possible lineage or shared development influence.