Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8fc71f038c55581…

MALICIOUS

PDF

6.4 KB Created: 2009-10-25 20:35:22 Authoring application: Scribus 1.3.5svn (via Scribus PDF Library 1.3.5svn)
MD5: 19177e4231c92ea505ea5c2d5cee2347 SHA-1: 0b9eca1c69285be45abfb3a4f92122e0c0dd7adc SHA-256: d8fc71f038c555814b12a943296bbe1044594f1afc03673c00c6576f4365293b
66 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript stream is obfuscated using unescape() and String.fromCharCode, suggesting malicious intent. The primary function of the script appears to be downloading and executing a second-stage payload, as evidenced by the extracted artifact 'javascript_obj0013_001.js'. The obfuscation and the nature of the script point towards a downloader or droppper functionality.

Heuristics 5

  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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_obj0013_001.js
fb1b1c0b124478cc41cad9ba52d8487bc7604455fe4fcb550e3299c2e5dce773
pdf-javascript-stream PDF /JS object 13 at offset 0xC11 11101 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).