Malicious PDF — malware analysis report

Static analysis result for SHA-256 8797219c21eb12d9…

MALICIOUS

PDF

291.8 KB
MD5: de2d09118c89bc571e164317acc60e24 SHA-1: 7dc3d2f964977d1ca53bd67e55fb877c4da04a01 SHA-256: 8797219c21eb12d9e128ef1ca1e2cbb7da849b604e919f033c34c6359ffc4768
76 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Phishing: Spearphishing Attachment T1027 Obfuscated Files or Information

The PDF file 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, named 'javascript_obj0008_000.js', is likely responsible for executing malicious code, potentially downloading and running a second-stage payload. The use of obfuscation techniques like fromCharCode and ASCIIHexDecode further supports malicious intent.

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
d427dbc42c21d3885f7e24982a1f0d97c6c43f0c1ebe7c91000d0ffb3eb3cf9e
pdf-javascript-stream PDF /JS object 8 at offset 0x1CE 99336 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).