Malicious PDF — malware analysis report

Static analysis result for SHA-256 d37bb9c9b1a4ac08…

MALICIOUS

PDF

292.8 KB
MD5: 05c597e8257a99a1d706d7532862e580 SHA-1: 8927509d8418bc5c158ce41624401df8a80e7323 SHA-256: d37bb9c9b1a4ac08dfadf5d9640b70d15f9972c2a5b10899c165529d955fb2aa
76 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell

The PDF contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The ML classifier strongly flags this PDF as malicious. The embedded JavaScript file, 'javascript_obj0008_000.js', is likely responsible for executing a malicious payload, potentially involving obfuscated code as suggested by the static triage.

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.
  • 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)
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
cd80318a95ed335e3863f356ee79d08bfaa61239a51e3ea1df042e4307871363
pdf-javascript-stream PDF /JS object 8 at offset 0x1CE 99672 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).