Multiminer

Overview

CoinMiner:Win32/Multiminer represents a prevalent class of malware known as **Cryptojackers or Cryptocurrency Miners**. Unlike ransomware that destroys data, Multiminer's objective is entirely parasitic: it silently hijacks the infected computer's processing power (CPU and/or GPU) to solve complex cryptographic algorithms, mining cryptocurrency (like Monero or Bitcoin) and sending the profits directly to the attacker's wallet.

Understanding Multiminer (Cryptojacking)
To an end-user, the primary symptom of a Multiminer infection is severe system sluggishness. The computer's fans will spin constantly at maximum speed, applications will hang, and laptop batteries will drain rapidly. For an enterprise, widespread cryptomining infections represent a massive, unauthorized consumption of electricity and cloud computing resources, resulting in tangible financial loss and hardware degradation.

Execution and Resource Hijacking Mechanics
Multiminer is often distributed via opportunistic botnets scanning for unpatched vulnerabilities (like EternalBlue), malicious email attachments (`T1566.001`), or bundled with pirated software. Upon execution, it establishes persistence, often running as a hidden Windows Service (`T1543.003`) or via a scheduled task. The core payload (`T1496`) is a mining binary (often a modified version of open-source tools like XMRig). The malware configures the miner to connect to a specific mining pool over the internet (`T1071.001`), providing the attacker's wallet address. Advanced variants use defense evasion techniques to detect if Task Manager or security tools are opened, temporarily pausing the mining process to avoid detection (`T1562.001`).

Indicators of Compromise & Impact
The impact is significant resource theft, hardware wear, and inflated cloud infrastructure bills. Host-based IoCs include EDR alerts for sustained, 100% CPU/GPU utilization by unknown processes (often disguised as `svchost.exe` or `wuauclt.exe`). Network IoCs are highly distinct: consistent, unencrypted TCP connections to known cryptocurrency mining pools (e.g., using the Stratum protocol on ports 3333, 14444, or 443).

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the MITRE ATT&CK framework:

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_MULTIMINER {
    meta:
        description = "Detects Multiminer (ransomware)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "multiminer" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Multiminer Activity
id: ef69f34ba02e92a9530e85db226c11db
status: experimental
description: Detects generic indicators of the multiminer malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*multiminer*"
    condition: selection
level: medium

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Isolate the endpoint to immediately sever the connection to the mining pool and halt the unauthorized resource consumption.
2. Use EDR or Process Explorer to identify the heavily obfuscated mining process consuming CPU cycles and terminate it.
3. Audit Windows Services and Scheduled Tasks to locate and remove the persistence mechanisms used to restart the miner.
4. Implement network-level blocking of known cryptocurrency mining pool IP addresses and domains at the corporate firewall.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not ignore complaints of 'slow computers'; while often a benign IT issue, widespread sluggishness is a primary indicator of a cryptojacking outbreak.
2. Avoid assuming cryptominers are harmless; threat actors often deploy miners as a secondary payload after establishing a backdoor, meaning data theft may have also occurred.

References & External Analysis

• Search "multiminer" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: ransomware)

Explore other malware families in the same category:

• Multipacked
• Glox
• Inservice
• Shadowbrokers
• Huhk

Machine-readable

Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/multiminer.json

Ecosystem & Interactive Environments

This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.