Full Report
The Linuxsys cryptominer is part of a long-running campaign active since at least 2021, consistently exploiting multiple web application vulnerabilities to deploy the Linuxsys coinminer on compromised systems. The attacker utilizes a stable methodology: exploiting n-day vulner...
Analysis Summary
# Tool/Technique: Linuxsys Cryptominer Campaign
## Overview
A long-running, stable cryptomining campaign active since at least 2021. Its primary goal is resource hijacking by exploiting web application vulnerabilities to deploy the Linuxsys coinminer.
## Technical Details
- Type: Campaign
- Platform: Linux (targeting web servers running Apache HTTP Server)
- Capabilities: Remote code execution via web vulnerabilities, deployment of coinminer, establishment of persistence via cron jobs.
- First Seen: At least 2021
## MITRE ATT&CK Mapping
- **TA0001 - Initial Access**
- T1190 - Exploit Public-Facing Application
- T1190.003 - Exploit Vulnerability Staging (Implied via persistent exploitation of known vulnerabilities)
- **TA0003 - Persistence**
- T1547.001 - Boot or Logon Autostarts: Registry (Not applicable/Linux equivalent used)
- T1547.006 - Boot or Logon Autostarts: Component Object Model Hijacking (Not applicable)
- **(Implied)** T1053.003 - Scheduled Task/Job: Cron
- **TA0011 - Command and Control**
- T1071.001 - Application Layer Protocol: Web Protocols (Used for downloading payloads)
## Functionality
### Core Capabilities
- Exploiting **n-day/1-day vulnerabilities** in web servers to gain initial access.
- Deploying an initial dropper script (`linux.sh`).
- Downloading the main miner payload (Linuxsys coinminer), configuration files, and persistence mechanisms from compromised legitimate websites.
- Establishing persistence using **cron jobs**.
- Utilizing the **XMRig** framework for Monero mining.
### Advanced Features
- **Stable Methodology:** Consistent, long-term operational uptime (since 2021) through disciplined vulnerability exploitation and infrastructure management.
- **Evasion:** Leveraging third-party compromised hosts for staging malware and using trusted domains for payload delivery to evade security controls.
## Indicators of Compromise
- File Hashes: [Not provided in the text]
- File Names: `linux.sh` (initial dropper script)
- Registry Keys: [Not applicable/Linux environment]
- Network Indicators:
- Mining Pool: `hashvault[.]pro`
- Behavioral Indicators:
- Execution of web-initiated scripts leading to the download of mining software.
- Creation of persistent cron jobs related to binary execution.
## Associated Threat Actors
- Actors are listed as **Unknown** in the provided context, characterized by sustained, resource-focused activity.
## Detection Methods
- Signature-based detection: Signatures for the specific XMRig configuration or the Linuxsys coinminer binary.
- Behavioral detection: Detection of suspicious processes spawned by web server processes (e.g., Apache child processes executing shell scripts or downloading large binaries). Detection of new cron jobs added by web application contexts.
- YARA rules: [Not available in the text]
## Mitigation Strategies
- **Patch Management:** Immediately apply patches for known vulnerabilities, specifically concerning exploited CVEs (e.g., CVE-2021-41773, and others from 2023-2024).
- **Web Application Security:** Implement strong Web Application Firewalls (WAF) and perform continuous vulnerability scanning of public-facing applications.
- **Principle of Least Privilege:** Ensure web server processes run with the absolute minimum necessary privileges to prevent file modification or execution of system binaries.
- **Monitoring:** Monitor user/service accounts associated with web roots for unexpected additions to system scheduling mechanisms (cron jobs).
## Related Tools/Techniques
- **XMRig:** The actual Monero mining software utilized by the campaign.
- **Cryptomining:** General malware category/objective.
- **Vulnerability Exploitation:** The consistent initial access vector.