Malicious PDF — malware analysis report

Static analysis result for SHA-256 8511bc201da39dc5…

MALICIOUS

PDF

4.0 KB
MD5: 3fee8dee086724961287b876ac43f93e SHA-1: 0a7f36753c7cfd25bf6cc138095f5c99d166931e SHA-256: 8511bc201da39dc556077e9ff13a4b060d0e34253835802f4ee3d597684d3b93
76 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, indicated by PDF_JAVASCRIPT and PDF_JS heuristics. The ML classifier strongly flags this PDF as malicious. The JavaScript appears obfuscated but includes a call to 'eval' with a string manipulation that reconstructs to 'eval(s.split(" ").join("").replace("swf","pdf"))'. This suggests the script attempts to dynamically construct and execute code, likely to download and run a secondary payload. The PDF_FILTER_HEX heuristic also indicates potential exploit activity.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.