Johnnie

Overview

Johnnie (tracked in threat databases as Trojan:Win32/Johnnie, HackTool:Win32/Johnnie, and Worm:Win32/Johnnie) is a Windows trojan, reconnaissance hacktool, and payload dropper discovered in the wild around 2012. Engineered to perform local network discovery, privilege assessment, and unauthorized access, Johnnie is frequently deployed by threat actors following initial network intrusion. Upon execution, Johnnie scans the local subnet for open network shares, active SMB services, and accessible administrative shares (admin$, c$). It attempts credential-spraying routines against discovered network nodes using default administrative credentials. Furthermore, Johnnie establishes persistence by copying its binary into system folders, registering Windows autostart services, and beaconing out to operator infrastructure to download secondary malware modules.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan:Win32/Johnnie
• HackTool:Win32/Johnnie
• Worm:Win32/Johnnie
• Win32/Johnnie.A
• Johnnie.Tool

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Derived From / Upstream Ancestry: Win32 Reconnaissance Toolkits

Known Derivatives & Downstream Variants: Johnnie.A · Johnnie.Hacktool · Johnnie.Gen

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

Tactical Mitigations

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

• T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4
• 9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a

Delivery vectors

• Lateral movement using compromised administrative SMB credentials
• Bundled installer downloads from untrusted software repositories

Persistence mechanisms

• HKLM\Software\Microsoft\Windows\CurrentVersion\Run\JohnnieService
• %WINDIR%\System32\johnnie_sys.exe

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:

rule MALWARE_WIN_JOHNNIE_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Johnnie"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "johnnie" ascii wide nocase
        $s2 = "trojan:win32/johnnie" ascii wide nocase
        $s3 = "hacktool:win32/johnnie" ascii wide nocase
        $s4 = "worm:win32/johnnie" ascii wide nocase
        $s5 = "win32/johnnie.a" ascii wide nocase
        $s6 = "johnnie.tool" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Johnnie (Trojan) Execution & Triage
id: 0f73d307-721e-5077-8bef-8fe830e1149c
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Johnnie malware family. Detects suspicious execution from temporary user
  directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/johnnie
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-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.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1083
- attack.t1046
- attack.t1059_003
- attack.t1547_001
- attack.t1105
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \cscript.exe
    - \wscript.exe
    CommandLine|contains:
    - AppData\Local\Temp
    - -WindowStyle Hidden
    - /e:jscript
    - bitsadmin /transfer
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: medium

rule MALWARE_WIN_JOHNNIE_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Johnnie 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 = "johnnie" 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.

1. Isolate the compromised system from the network to halt lateral SMB network scanning.
2. Terminate active Johnnie processes using Task Manager or administrative command prompts.
3. Remove persistence keys under HKLM\Software\Microsoft\Windows\CurrentVersion\Run.
4. Audit network accounts for failed login spikes and reset administrative credentials.

What to Avoid

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

1. Do not reuse administrative passwords across multiple network workstations.
2. Avoid leaving open write access on administrative network file shares.

References & External Analysis

• Zscaler ThreatLabz - Win32.Trojan.Johnnie Analysis
• Trend Micro Threat Encyclopedia - Trojan.Win32.Johnnie
• Search "johnnie" on VirusTotal (External Analysis)
• Search "johnnie" on Any.Run (Sandbox Sandbox)
• Search "johnnie" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Yuri
• Gtbot
• Magala
• Krepper
• Redator
• Tspy
• Yoddos
• Byfh

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/johnnie.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.