Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5c5102795d7ebba…

MALICIOUS

PDF

37.7 KB
MD5: daab247a41e650f80883c284a967d086 SHA-1: 9f202e7ab706358d20656e564c5942de57ebb5c2 SHA-256: b5c5102795d7ebba7e061b5221931e4e7db56b9c99b3a8b9bc1e655210c07917
124 Risk Score

Malware Insights

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

The PDF file exhibits multiple indicators of malicious activity, including embedded JavaScript and Flash content. The ML classifier strongly flags this PDF as malicious. The presence of a JavaScript stream, identified as 'javascript_obj0006_000.js', suggests an attempt to execute code. The overall structure points towards a delivery mechanism for further exploitation or payload download.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector
  • 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
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Adobe.swf
ce5f7936cf8e3536a88a804ce2d6902022df1794fa878bdc64a26866e34ba989
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0xACF 55839 bytes
javascript_obj0006_000.js
416a343d10697f555bbe64a226539628f7e47c9c40c7f1a87e740afd46835280
pdf-javascript-stream PDF /JS object 6 at offset 0xF5 1588 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).