Malicious PDF — malware analysis report

Static analysis result for SHA-256 2591f328ded48ac4…

MALICIOUS

PDF

3.8 KB
MD5: c8701aa172fbfc60dc6b0ea1965f36f2 SHA-1: 5e0709fb37add0153b5815e6f2aa148efadf2d40 SHA-256: 2591f328ded48ac4961f18155f9acbe8409d3fb9ed11a0b7928de6f3b151bc18
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

This PDF file was flagged as malicious by a ClamAV signature and a machine learning classifier. Heuristics indicate the presence of embedded JavaScript, likely intended to exploit a PDF vulnerability. The JavaScript uses String.fromCharCode and ASCIIHexDecode/ASCII85Decode filters, common techniques for obfuscating malicious code within PDF documents. The ML classifier's high confidence score further supports the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • ClamAV: Pdf.Exploit.Agent-36178 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36178
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation