Malicious PDF — malware analysis report

Static analysis result for SHA-256 866bf9775ed9f148…

MALICIOUS

PDF

54.8 KB
MD5: c7e5e1986d5f2333b9e83d38455f246c SHA-1: 9950b8407f430401394110432145b38f60c0682e SHA-256: 866bf9775ed9f148f5a5727d27340a520c0087a63c890741d71d9148030cd3fd
226 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF sample contains embedded JavaScript that leverages the CVE-2009-4324 vulnerability, specifically by calling the 'media.newPlayer' function. This JavaScript is heavily obfuscated but appears designed to download and execute a secondary payload. The ML classifier strongly indicates maliciousness, and the exploit cluster points to a known vulnerability.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • Suspicious extracted artifact medium 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.
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
a6a0408d1618a78fb4a8e8a44d2c2daf6f34c5a9883a9f8814df95d1ac3c1101
pdf-javascript-stream PDF /JS object 8 at offset 0x210 2960 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 3 long hex-escaped blob(s).
legacy_pdfkit_stage_000.js
42c3f4df375ff6f58ff655cc4f88b5cc28f0dd33b978390db3538684a6219b74
deobfuscated-js string-concatenation normalized Acrobat API aliases at offset 0x210 126 bytes