Malicious PDF — malware analysis report

Static analysis result for SHA-256 64c4aa0147163684…

MALICIOUS

PDF

40.0 KB
MD5: 25f9766b6a8e6e2a59c248394d7a9619 SHA-1: 35f731fbc9a42fd96e1a0d9820d491e5765c571b SHA-256: 64c4aa01471636845951ef143efd3a6f9ef15bc210dd7f397f9325ab8fff603a
270 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript that exploits CVE-2009-4324, as indicated by the 'CVE_2009_4324' heuristic. The JavaScript is designed to download a second-stage payload from the URL http://vexys.com/new/post.php?e=8&&. This is further supported by the 'PDF_JS_SHELLCODE_DOWNLOAD_URL' heuristic and ClamAV detections.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • 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)
  • ClamAV: Win.Trojan.Agent-36169 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36169
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • PDF JavaScript shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF JavaScript shellcode contains a hardcoded http(s) URL stored as little-endian %uXXXX Unicode escapes. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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.
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://vexys.com/new/post.php?e=8&&

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
8d80706fb3c06713515c47dc3323b50052743b24b2a6d2954b10088cf010fdd4
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2019 bytes
Detection
ClamAV: Win.Trojan.Agent-36169
Obfuscation or payload: unlikely
javascript_obj0008_001.js
6924fcf71d4cf86849a23b6135b3ed74e91c10d699048dbcd47ebe3ffaeb3fd9
pdf-javascript-stream PDF /JS object 8 at offset 0x209 40427 bytes
Detection
ClamAV: Win.Trojan.Agent-36169
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_000.js
dd93350d7e7d17f9d32b4dbab484694241353a254b3d770d956c991f0e1733f8
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x9FE 2540 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
42025b552c7960b53abcd8cd732b01c8d109eccfdfefc352b9826c4d5807d414
deobfuscated-js cross-stage annotation API aliases at offset 0x1E7 81 bytes