Dimnie

Overview

Trojan:Win32/Dimnie is a highly stealthy, targeted espionage trojan that was notably active around 2017. Unlike broad-spray banking trojans, Dimnie was highly specialized, focusing specifically on exfiltrating source code, developer credentials, and intellectual property. It gained infamy for aggressively targeting software developers, system administrators, and specifically users active on platforms like GitHub.

Understanding Dimnie
To an infected developer, Dimnie is completely invisible. It is designed for long-term intelligence gathering, not immediate financial fraud or destruction. For a threat intelligence analyst, Dimnie represents a targeted supply chain threat. By compromising developers, the attackers aim to steal proprietary source code or inject malicious code into the victim organization's software products. Dimnie is notable for its extremely sophisticated modular architecture, where the core payload executes entirely in memory (fileless execution) to evade detection.

Execution and Espionage Mechanics
Dimnie is typically distributed via highly tailored spearphishing emails targeting developer email addresses, often masquerading as job offers or urgent bug reports with weaponized attachments (`T1566.001`). Upon execution of the initial dropper, it utilizes advanced process hollowing (`T1055.012`) to inject its core module directly into legitimate system processes (like `explorer.exe`). It establishes persistence via hidden Scheduled Tasks. The core module then reaches out to the C2 to download specialized espionage plugins directly into memory (`T1620`). These plugins include advanced keyloggers (`T1056.001`), clipboard monitors (looking for copied API keys or passwords), and modules specifically designed to search the hard drive and network shares for source code files (e.g., `.cpp`, `.py`, `.sln`) and exfiltrate them (`T1005`).

Indicators of Compromise & Impact
The impact is the devastating loss of intellectual property and potential supply chain compromise. Incident responders will find little to no trace of the main payload on the hard drive. Detection relies heavily on EDR behavioral analysis. Look for anomalous network traffic originating from `explorer.exe` (or similar core processes) communicating over non-standard ports or using heavily disguised HTTP traffic. Memory forensics (RAM dumping) is absolutely critical to extract the active Dimnie modules and identify the exfiltrated data.

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:

• T1056.001: Implement Endpoint Detection and Response (EDR) to monitor for suspicious API calls related to keystroke interception. Enforce Multi-Factor Authentication (MFA) to render stolen passwords useless.
• T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.

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

Sigma Rule

title: Suspicious Dimnie Activity
id: c202eaff09e2c01343a4098a1407b043
status: experimental
description: Detects generic indicators of the dimnie malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*dimnie*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Instantly isolate the endpoint; an active Dimnie infection means an advanced threat actor is actively stealing source code and credentials.
2. Assume all local credentials, SSH keys, GitHub tokens, and AWS access keys present on the machine are compromised. Revoke them immediately.
3. Capture a full forensic memory image (RAM dump) to extract the fileless espionage plugins and determine exactly what data was targeted for exfiltration.
4. Perform a complete bare-metal rebuild of the operating system; fileless malware leaves persistence hooks that are extremely difficult to guarantee removed.

What to Avoid

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

1. Do not assume the code repositories accessed by the victim are safe; audit all recent commits made by the compromised user for malicious injections.
2. Avoid relying on standard antivirus scans, as Dimnie's core logic and plugins exist almost entirely in volatile memory.

References & External Analysis

• Search "dimnie" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: trojan)

Explore other malware families in the same category:

• Zebrocy
• Tenga
• Ntrootkit
• Skeeyah
• Potao

Machine-readable

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