Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a48ab29b98b720d…

MALICIOUS

PDF

3.8 KB
MD5: b1e6bdb6f65b13b446270f67d763d3ba SHA-1: 171bda45356e69b203bbb0fc88f776ea27228418 SHA-256: 3a48ab29b98b720d83c490c34eb29c7bb045edcac9ee1d0098e4f001e203f1cd
142 Risk Score

Malware Insights

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

The file is a PDF containing embedded JavaScript, which is a common technique for exploiting PDF reader vulnerabilities. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of JavaScript actions and streams, along with the use of ASCIIHexDecode and ASCII85Decode filters, suggests the PDF is attempting to obfuscate and execute malicious code, likely to download and run a second-stage payload.

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