Idlebuddy
Table of Contents
Overview
PUA:Win32/Idlebuddy is a persistent Potentially Unwanted Program (PUA) that functions primarily as a stealthy **Cryptominer** and distributed computing node. It is designed to hijack the infected endpoint's CPU and GPU resources to mine cryptocurrency (often Monero) for the developers, specifically engineering its execution to only occur when the user is away from the computer to evade detection.
Understanding the Idlebuddy Threat
To an end-user, Idlebuddy is designed to be invisible. They might occasionally notice the computer's fans spinning loudly when they walk into the room, but the noise stops as soon as they move the mouse. For an enterprise, Idlebuddy represents the theft of computing resources (Cryptojacking), resulting in increased electricity costs, hardware degradation, and severely reduced endpoint lifespan.
Execution and Evasion Mechanics
Idlebuddy is heavily distributed via software bundlers, often hidden inside installers for free games or utility software (`T1189`). Upon execution, it installs itself deeply into the system, establishing persistence via Registry Run keys or hidden Scheduled Tasks (`T1547.001`). Its defining characteristic is its evasion routine (`T1489`). It utilizes Windows APIs (like `GetLastInputInfo`) to monitor keyboard and mouse activity. The actual mining payload (often a modified version of XMRig) is only launched when the system has been completely idle for a specific duration (e.g., 10 minutes). The moment the user moves the mouse or opens the Task Manager, Idlebuddy instantly suspends or kills the mining process, dropping CPU usage back to normal before the user can see what was causing the lag.
Indicators of Compromise & Impact
The primary impact is resource theft and hardware wear. Host-based IoCs include EDR alerts for the creation of processes resembling known cryptominers (e.g., `ib.exe`, `idlebuddy.exe`), or sudden, massive spikes in CPU/GPU utilization that immediately drop when a user logs in. Network IoCs include continuous outbound traffic to known cryptocurrency mining pools (e.g., Stratum protocol traffic) over non-standard ports (like 3333 or 4444) when the machine is locked.
MITRE ATT&CK Techniques
Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:
| Technique | Name | Tactic | Official Spec |
|---|---|---|---|
T1496 | Resource Hijacking (Cryptomining) | Impact | ATT&CK ↗ |
T1189 | Drive-by Compromise (Bundled Installers) | Initial Access | ATT&CK ↗ |
T1547.001 | Boot or Logon Autostart Execution: Registry Run Keys | Persistence | ATT&CK ↗ |
T1489 | Service Stop (Suspending the miner when Task Manager opens) | Defense Evasion | ATT&CK ↗ |
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-RBI | Remote Browser Isolation | Isolate | T1189 | Execute untrusted web browsing sessions in disposable cloud containers to isolate drive-by exploits from local endpoints. |
D3-SPP | Service Protection Policies | Harden | T1489 | Configure strict DACLs on Windows Service Control Manager to prevent unauthorized termination of antivirus and backup services. |
D3-PEA | Processor Execution Auditing | Detect | T1496 | Alert on sustained high CPU/GPU utilization by processes originating from temporary user directories and block stratum mining pool ports. |
D3-RPM | Registry Persistence Monitoring | Detect | T1547.001 | Audit and restrict write privileges to user and machine-level Registry Run/RunOnce keys using Endpoint Privilege Management. |
Tiered Detection Rules (Cisco CAIRN Model)
Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_IDLEBUDDY_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Idlebuddy"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "idlebuddy" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Idlebuddy (Advanced Threat) Execution & Triage
id: a07acef3-35ce-5289-a401-011427745c9c
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Idlebuddy malware family. Detects proxy execution, reflective DLL loading,
and remote command injection associated with modular enterprise backdoors.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/idlebuddy
- https://malware-families-catalog.systemhelpdesk.com/defensive/backdoor-rat-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.advanced-threat
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1496
- attack.t1489
- attack.t1189
- attack.t1547_001
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \powershell.exe
- \cmd.exe
- \rundll32.exe
- \regsvr32.exe
CommandLine|contains:
- DownloadString
- IEX(
- '/s /n /u /i:'
- sc create
- start-process
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: highTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_IDLEBUDDY_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Idlebuddy tradecraft"
tier = "T3 - Attribution Fingerprint"
confidence = "High (Confirmed Family Signature)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
// Core family identifier & heuristic payload signatures
$attrib_str = "idlebuddy" ascii wide nocase
$pe_magic = "MZ" ascii
$net_marker = "http" ascii nocase
condition:
uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}Containment & Response Steps
Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.
- Use the Windows Control Panel to attempt uninstallation of the software; however, Idlebuddy often uses deceptive uninstallers that leave the mining components behind.
- Deploy an enterprise adware/PUA removal tool to locate and strip the hidden scheduled tasks and registry hooks.
- Review firewall logs for any endpoints establishing long-lived TCP connections to known cryptocurrency mining pools, and block those IPs at the perimeter.
- If the software was installed without administrative privileges, audit the user's `%AppData%` folder for the hidden executables.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not rely solely on the Windows Task Manager to find the malware, as its primary evasion tactic is to hide from it.
- Avoid ignoring cryptominers; while they don't steal data, the initial access vector that allowed the miner in could be used to deploy ransomware next time.
References & External Analysis
- Search "idlebuddy" on VirusTotal (External Analysis)
- Search "idlebuddy" on Any.Run (Sandbox Sandbox)
- Search "idlebuddy" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Idlebuddy and what threat category does it belong to?
Idlebuddy is classified as a Advanced Threat. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments.
How does Idlebuddy establish persistence and evade defensive controls?
Idlebuddy typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks.
What are the essential incident response steps for mitigating a Idlebuddy compromise?
Security teams responding to Idlebuddy should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups.
What lateral movement and credential access tactics does Idlebuddy leverage in enterprise intrusions?
Idlebuddy frequently utilizes privileged account harvesting techniques such as LSASS memory dumping, Kerberoasting, and token impersonation to escalate privileges. Once administrative credentials are acquired, it pivots across the victim network utilizing living-off-the-land binaries (LOLBins) such as WMI, PowerShell remoting, and PsExec, or abuses remote desktop protocols (RDP) to reach critical internal repositories and domain controllers.
How does Idlebuddy maintain covert communications and evade perimeter network monitoring?
Idlebuddy often relies on multi-stage command and control (C2) architectures utilizing encrypted protocols over standard web ports (HTTPS/443 or DNS tunneling) to blend in with legitimate enterprise network traffic. Many variants incorporate proxy networks, domain fronting, or cloud services (such as Microsoft Graph API, Google Drive, or Telegram) to masquerade C2 channels, bypassing traditional signature-based egress filtering.
How do I remove the Idlebuddy Advanced_Threat from Windows?
Manual removal of Idlebuddy is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Idlebuddy a virus or a Advanced_Threat?
Idlebuddy is classified as a Advanced_Threat. Unlike traditional viruses that infect files, modern malware like Idlebuddy typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Idlebuddy infection?
Symptoms of Idlebuddy can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Protect Your Network Against Advanced_Threats
Want to prevent Idlebuddy and similar threats from compromising your organization? Read our comprehensive defensive guide: Think You've Been Hacked? What To Do First.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
Machine-readable
Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/idlebuddy.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.