{
  "family": "scramupx",
  "sample_count": 1,
  "category": "advanced_threat",
  "description": "<h3>Executive Summary</h3>\nScramUPX is a highly specialized malware packing and obfuscation utility. It is designed to take an executable file that has already been compressed with UPX (Ultimate Packer for Executables) and \"scramble\" or alter the UPX header and internal structure. The explicit goal of ScramUPX is to intentionally break standard, automated UPX unpacking routines used by antivirus engines and malware sandboxes, thereby preventing security tools from scanning the underlying malicious payload.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nScramUPX itself is not malware; it is a tool used by threat actors *before* deployment. If an endpoint security solution detects a file as packed with ScramUPX, it is a highly suspicious indicator that the author went to great lengths to evade detection.\n\nTechnically, ScramUPX operates by manipulating PE headers:\n<ul>\n<li><strong>UPX Evasion:</strong> UPX is a legitimate compression tool, and most AV engines have built-in routines to automatically decompress UPX files for scanning. ScramUPX modifies the UPX \"magic numbers,\" section names, and the decompression stub within the executable.</li>\n<li><strong>Anti-Analysis:</strong> When an AV engine encounters the scrambled file, its automated UPX unpacker fails because the expected structure is invalid. The AV is then forced to scan only the scrambled, compressed data, which rarely matches known malware signatures.</li>\n<li><strong>Execution:</strong> Despite the scrambled headers, the threat actor ensures the modified executable still contains a functional, albeit non-standard, unpacking stub that allows the payload to successfully execute and decompress itself in memory when run by the victim.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nThe detection of a ScramUPX-packed executable in a corporate environment is a high-severity alert. Legitimate software developers do not use ScramUPX. Its presence strongly implies an active attempt to bypass endpoint security controls to deploy an unknown, potentially highly destructive payload.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Isolation and Triage:</strong> Isolate the endpoint. Do not attempt to run the file to see what it does.</li>\n<li><strong>Dynamic Analysis (Sandboxing):</strong> The only effective way to determine the true nature of a ScramUPX-packed file is to execute it in a secure, isolated malware sandbox (e.g., Cuckoo Sandbox) and observe its behavioral telemetry (network connections, process injection).</li>\n<li><strong>Memory Forensics:</strong> If the file has already been executed, traditional file scanning is useless. Incident responders must capture the system's RAM and perform memory forensics to extract the uncompressed malicious payload that is currently running in memory.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Packer.ScramUPX",
    "Tool.UPXScrambler",
    "Obfuscator.Win32"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1027.002",
    "T1562.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-02T07:38:22Z",
  "type": "Tool / Packer",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}