Zoldon

Overview

Executive Summary

Infection Vector and Technical Capabilities

• System Hooking and Persistence: The trojan deeply embeds itself within the operating system, often injecting its code into legitimate processes (like `explorer.exe` or `svchost.exe`) to hide from task managers and ensure it launches automatically upon system boot (modifying `Run` keys or creating hidden services).
• Botnet Command and Control: Zoldon silently connects to a remote Command and Control (C2) server. It registers the infected machine, transmits basic system profiling data, and awaits commands from the botmaster.
• Malicious Execution: Based on C2 instructions, the infected machine may participate in coordinated DDoS attacks against external targets, download and execute secondary malware payloads, or open hidden proxy ports to allow attackers to route traffic through the corporate network.

Threat Assessment

Remediation and Eradication

• Network Isolation and C2 Blocking: Immediately isolate the infected endpoint from the LAN. Analyze firewall logs to identify the outbound C2 IP addresses and block them at the perimeter to sever the botmaster's control.
• Behavioral Analysis (EDR): Utilize Endpoint Detection and Response (EDR) to identify the specific processes Zoldon has injected into and to trace any secondary payloads it may have downloaded.
• Complete Re-imaging: Due to the deep system hooking and the potential for secondary backdoor installations, attempting to manually "clean" a botnet node is highly risky. The most secure remediation is a complete bare-metal wipe and re-image from a trusted corporate baseline.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan.Zoldon
• Botnet.Zoldon
• Win32/Zoldon

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:

• 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):

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_ZOLDON_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Zoldon"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "zoldon" ascii wide nocase
        $s2 = "trojan.zoldon" ascii wide nocase
        $s3 = "botnet.zoldon" ascii wide nocase
        $s4 = "win32/zoldon" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Zoldon (Ransomware) Execution & Triage
id: 47ebf03f-7c97-587f-8a54-c279f023eb35
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Zoldon malware family. Detects volume shadow copy deletion, boot status
  tampering, and recovery inhibition characteristic of modern ransomware operations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/zoldon
- https://malware-families-catalog.systemhelpdesk.com/defensive/ransomware-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.ransomware
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1055
- attack.t1105
- attack.t1547_001
- attack.t1498
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \vssadmin.exe
    - \wmic.exe
    - \wbadmin.exe
    - \bcdedit.exe
    CommandLine|contains:
    - delete shadows
    - shadowcopy delete
    - resize shadowstorage
    - recoveryenabled no
    - ignoreallfailures
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: critical

rule MALWARE_WIN_ZOLDON_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Zoldon 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 = "zoldon" 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. Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Zoldon from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.
2. Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Zoldon symmetric encryption keys or uncompiled payload components may still reside in memory.
3. Audit process execution logs and terminate active scripting interpreters (e.g. PowerShell, CMD, WScript) or commands executing 'vssadmin.exe delete shadows' or 'wbadmin' used by Zoldon to inhibit recovery.
4. Investigate the initial compromise vector (such as exposed RDP instances, spearphishing attachments, or vulnerable edge gateways) and enforce an immediate credential reset for all compromised Active Directory accounts.
5. Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Zoldon binary and related persistence hooks are eradicated.

What to Avoid

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

1. Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Zoldon.
2. Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.
3. Do not connect clean backup drives or external storage to the affected network until Zoldon eradication is completely verified.

References & External Analysis

• Search "zoldon" on VirusTotal (External Analysis)
• Search "zoldon" on Any.Run (Sandbox Sandbox)
• Search "zoldon" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Winiga
• Genericrxaq
• Foler
• Candybox
• 0Y1A48Lx2Yib
• Povertel
• Windapp
• Mutuodo

Machine-readable

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