Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef7e82708f1bae1c…

MALICIOUS

PDF

37.7 KB
MD5: e14c420a1f5d1b0b3792d516eac97ccc SHA-1: 136772381cea245ae61a336c65b3bea01b5241a3 SHA-256: ef7e82708f1bae1cb44fb06aa74999163017641a6efa0f7abfa34b426991c1c5
126 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, and a high ML classifier score. The presence of a JavaScript stream, identified as 'javascript_obj0006_000.js', suggests an attempt to execute code. The 'ML_NYX_PDF_MALICIOUS' heuristic firing with a score of 0.999988 strongly indicates malicious intent, likely involving the exploitation of PDF vulnerabilities or the delivery of a secondary payload via the embedded Flash or JavaScript.

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 0xAC9 55839 bytes
javascript_obj0006_000.js
0775489dba64ebc9116510215a015f8e352549cb4e41b328599a5fb053102f21
pdf-javascript-stream PDF /JS object 6 at offset 0xF5 1576 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).