Neksminer

Overview

Trojan:Win32/Neksminer is a specialized, stealthy cryptocurrency mining trojan designed to hijack the CPU and GPU resources of infected endpoints to illicitly mine digital currencies (typically Monero) for the threat actor.

Understanding Neksminer
To the victim, a Neksminer infection manifests as severe system sluggishness, high fan speeds, and unresponsive applications. For a security analyst, Neksminer represents a 'Cryptojacking' threat. Unlike ransomware, which announces its presence, Neksminer's goal is long-term stealth. It aims to remain undetected on corporate networks, quietly siphoning computational power and electricity, which can lead to significant hardware degradation and increased cloud computing costs.

Execution and Cryptojacking Evasion
Neksminer is typically distributed via drive-by downloads, exploit kits, or bundled with pirated software (`T1189`). Upon execution, it drops a modified, open-source mining executable (such as XMRig) into a hidden folder in `%AppData%`. To evade detection, it employs Process Hollowing (`T1055.012`), injecting the mining code into a legitimate Windows process like `svchost.exe`, `notepad.exe`, or `conhost.exe`. Advanced variants include a watchdog mechanism: if the user opens Task Manager (`taskmgr.exe`), the malware instantly suspends the mining operation to hide the CPU spike, resuming only when Task Manager is closed (`T1562.001`).

Indicators of Compromise & Impact
The primary impact is resource exhaustion (`T1496`) and financial loss (electricity/cloud billing). EDR platforms should alert on process hollowing into system executables. Network logs will reveal the malware communicating with known cryptocurrency mining pools (e.g., via the Stratum protocol) over non-standard ports (like TCP 3333 or 14444). Anomalous, sustained CPU usage near 100% across multiple endpoints is a strong indicator of a cryptojacking botnet.

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:

• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.

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

Sigma Rule

title: Suspicious Neksminer Activity
id: 92965e8fe17bd7d18524c76ef6c076d5
status: experimental
description: Detects generic indicators of the neksminer malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*neksminer*"
    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 from the network to sever the malware's connection to its mining pool, halting its ability to receive new hashing tasks.
2. Use EDR tools to identify the hollowed system process (e.g., svchost.exe consuming massive CPU) and terminate the specific malicious PID.
3. Audit firewall logs for Stratum protocol traffic or connections to known mining pool IP addresses and block them enterprise-wide.
4. Check for and remove persistent scheduled tasks or registry keys ensuring the miner restarts upon reboot.

What to Avoid

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

1. Do not rely solely on Task Manager to diagnose the issue; sophisticated miners pause execution when monitoring tools are opened.
2. Avoid treating cryptojacking as a low-priority 'nuisance' threat; if the attacker could deploy a miner, they could have deployed ransomware.

References & External Analysis

• Search "neksminer" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: ransomware)

Explore other malware families in the same category:

• Xcomp
• Wyhymyz
• Hydracrypt
• Zbiw
• Davobevix

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/neksminer.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.