Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f1ab79b70c4b9af…

MALICIOUS

PDF

3.9 KB
MD5: 012bae28890a94df34f5c864181e2902 SHA-1: 81fd0dff3e320bbfd5da7a7e780938cf00fc7a85 SHA-256: 1f1ab79b70c4b9af6be27a0332820bde89430080ed93dbfc06d063791e28fd4b
142 Risk Score

Malware Insights

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

The critical ClamAV detection and high ML classifier score indicate this PDF is malicious. The presence of PDF_JAVASCRIPT, PDF_JS, and PDF_FROMCHARCODE heuristics, along with PDF_FILTER_HEX and PDF_FILTER_85 filters, strongly suggests the exploitation of a PDF vulnerability. The embedded JavaScript is likely designed to download and execute a second-stage payload, a common technique for initial access.

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