{
  "family": "zaxar",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nZaxar is a highly sophisticated Trojan and Botnet component that poses a severe threat to enterprise networks. While it functions as a downloader, it is specifically engineered to establish deep, persistent backdoors, recruit the infected host into a resilient botnet architecture, and act as a primary delivery mechanism for secondary, high-impact payloads such as banking trojans and enterprise ransomware.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nZaxar typically infiltrates networks via highly targeted spear-phishing campaigns utilizing malicious macro-enabled documents, or it is dropped silently via exploit kits that compromise vulnerable web browsers.\n\nOnce active, Zaxar employs advanced techniques for evasion and control:\n<ul>\n<li><strong>Process Injection and Hooking:</strong> Zaxar heavily utilizes Process Hollowing and API hooking. It decrypts its payload in memory and injects it into legitimate Windows processes (like `explorer.exe` or `svchost.exe`). This allows it to evade file-based AV detection and bypass local firewalls.</li>\n<li><strong>Resilient C2 Communication (DGA):</strong> To prevent defenders from simply blocking its Command and Control servers, Zaxar frequently employs Domain Generation Algorithms (DGA). It generates thousands of potential C2 domain names daily, making it extremely difficult to sever its connection to the botmaster.</li>\n<li><strong>Modular Payload Delivery:</strong> The Zaxar backdoor is highly modular. The botmaster can dynamically push down specific plugins to the infected endpoint based on its value (e.g., pushing an info-stealer if the machine belongs to the finance department, or a ransomware payload if the machine is a server).</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nA Zaxar infection is a critical security breach indicating a complete loss of endpoint integrity. The presence of this botnet client means the machine is under the active control of a sophisticated threat group, and the deployment of a catastrophic secondary payload (like ransomware) is imminent.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Network Isolation:</strong> Instantly sever the network connection of the infected machine to halt the C2 beaconing and prevent the download of the secondary payload.</li>\n<li><strong>Memory Forensics and Telemetry:</strong> Because Zaxar operates primarily in memory, traditional file scanning is insufficient. Use EDR telemetry and memory forensics to trace the injected processes and identify all anomalous network connections.</li>\n<li><strong>Mandatory Re-imaging and Credential Reset:</strong> The system must be wiped to bare metal and rebuilt from a clean image. All credentials utilized on or by the infected machine must be treated as compromised and immediately reset.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Botnet.Zaxar",
    "Trojan.Zaxar",
    "Backdoor.Win32.Zaxar"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Zaxar and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Zaxar is classified as a Ransomware. 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."
      }
    },
    {
      "@type": "Question",
      "name": "How does Zaxar establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Zaxar 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."
      }
    },
    {
      "@type": "Question",
      "name": "What are the essential incident response steps for mitigating a Zaxar compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Zaxar 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."
      }
    },
    {
      "@type": "Question",
      "name": "What cryptographic algorithms and file targeting techniques does Botnet.Zaxar employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Botnet.Zaxar typically leverages hybrid cryptographic architectures combining symmetric stream or block ciphers (such as AES-256 or ChaCha20) for rapid file encryption with asymmetric algorithms (such as RSA-2048 or Curve25519) to securely protect the session keys. It aggressively targets sensitive file extensions including corporate documents, databases, virtual disks, and backups while systematically executing commands to delete Volume Shadow Copies (vssadmin delete shadows /all /quiet) and disable system recovery options."
      }
    },
    {
      "@type": "Question",
      "name": "Are decryptors available for Botnet.Zaxar, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Botnet.Zaxar depends on whether security researchers or law enforcement (such as the No More Ransom initiative) have recovered the master private keys or discovered flaws in its key generation routines. Victims should never pay the extortion demand, as payment fuels criminal operations without guaranteeing file restoration. The recommended recovery procedure entails isolating infected hosts, conducting forensic disk imaging, identifying the root access vector, and restoring validated systems from immutable offline backups."
      }
    }
  ],
  "faq_count": 5,
  "mitre_attack": [
    "T1055",
    "T1568.002",
    "T1105"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Trojan / Botnet",
  "target_industries": [
    "Healthcare",
    "Critical Infrastructure",
    "Enterprise"
  ],
  "motivation": "Financial Extortion",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ],
  "attack_stage": [
    "defense_evasion",
    "impact"
  ],
  "ecosystem": [
    "windows_pe"
  ],
  "is_emerging": false,
  "mitre_attack_detail": [
    {
      "id": "T1055",
      "name": "Process Injection",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1568.002",
      "name": "Dynamic Resolution: Domain Generation Algorithms (DGA) (Evading C2 blacklisting)",
      "tactic": "Command and Control"
    },
    {
      "id": "T1105",
      "name": "Ingress Tool Transfer",
      "tactic": "Command and Control"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Zaxar from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.",
    "Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Zaxar symmetric encryption keys or uncompiled payload components may still reside in memory.",
    "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 Zaxar to inhibit recovery.",
    "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.",
    "Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Zaxar binary and related persistence hooks are eradicated."
  ],
  "what_to_avoid": [
    "Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Zaxar.",
    "Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.",
    "Do not connect clean backup drives or external storage to the affected network until Zaxar eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}