Dumpy

Overview

Trojan:Win32/Dumpy is a highly specialized malware variant designed specifically for **Credential Dumping**. Unlike a general-purpose backdoor, Dumpy has one primary objective: to extract cleartext passwords, password hashes (NTLM), and Kerberos tickets directly from the memory of the Local Security Authority Subsystem Service (`lsass.exe`) process on Windows machines.

Understanding Dumpy
To an end-user, a Dumpy infection is completely invisible; the system continues to operate normally. For an enterprise security team, Dumpy represents an immediate 'Code Red' escalation. The presence of this tool indicates that an attacker has already bypassed perimeter defenses, gained local administrator privileges, and is actively harvesting credentials to facilitate lateral movement across the network and escalate privileges to Domain Administrator.

Execution and Credential Theft Mechanics
Dumpy is almost never the initial infection vector. It is typically dropped post-exploitation by an attacker utilizing an existing backdoor (`T1105`) or executing living-off-the-land techniques via PowerShell. Upon execution, Dumpy requires `SeDebugPrivilege` to interact with `lsass.exe`. It uses Windows APIs (`MiniDumpWriteDump` or direct memory reading) to dump the memory space of the LSASS process (`T1003.001`). This memory dump contains the cryptographic secrets and hashes of any user who has recently logged into that specific machine. The attacker then parses this dump offline (using tools like Mimikatz or SecretsDump) to extract the credentials, which are then used in Pass-the-Hash (PtH) or Pass-the-Ticket (PtT) attacks against other systems on the domain.

Indicators of Compromise & Impact
The impact is a catastrophic breach of identity and authentication boundaries, often leading to total domain compromise. Host-based IoCs require robust EDR: look for any process (other than authorized administrative tools) attempting to open a handle to `lsass.exe` with `PROCESS_VM_READ` access rights. The creation of large, unexplained `.dmp` files in the `%Temp%` directory is a classic indicator. Network IoCs are minimal, as the dump is usually exfiltrated over an already established C2 channel.

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:

• T1003.001: Monitor for LSASS memory dumping or registry SAM extraction. Enable Credential Guard on Windows systems.
• T1059.001: Restrict execution of PowerShell. Enforce PowerShell Constrained Language Mode and Script Block Logging.

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

Sigma Rule

title: Suspicious Dumpy Activity
id: 74cb2c55bb4bc80dc748f6724a905c74
status: experimental
description: Detects generic indicators of the dumpy malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*dumpy*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Immediately isolate the endpoint to prevent the attacker from exfiltrating the memory dump or utilizing the stolen credentials for lateral movement.
2. Assume all accounts that recently logged into the compromised machine (especially Domain Admins) are compromised; initiate an immediate password reset for those accounts.
3. Enable Windows Defender Credential Guard (if not already active) across the enterprise to protect `lsass.exe` using virtualization-based security.
4. Hunt across the network for 'Pass-the-Hash' activity originating from the compromised endpoint targeting domain controllers or sensitive file shares.

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 attack is over if Dumpy is blocked; its presence proves the attacker already has high-level administrative access to the machine.
2. Avoid relying solely on signature-based detection for credential dumping, as attackers frequently recompile tools to change their hash and bypass static AV.

References & External Analysis

• Search "dumpy" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: trojan)

Explore other malware families in the same category:

• Suixin
• Udpos
• Drooptroop
• Remote
• Skypespam

Machine-readable

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