Malicious PDF — malware analysis report

Static analysis result for SHA-256 689676055152de0c…

MALICIOUS

PDF

6.8 KB
MD5: a70b6ace78ebd20f2855f2659eea663f SHA-1: 4699b5f6b9b56616e2b370ad6413e725fd1f7e8b SHA-256: 689676055152de0c119078b78b5b5658bb14c50e7706ffd968a8850025c9f93c
226 Risk Score

Malware Insights

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

The PDF utilizes JavaScript to exploit CVE-2014-0496, a known vulnerability for client execution. The embedded JavaScript contains a URL that is used to download a second-stage payload. The ML classifier strongly indicates maliciousness, and the presence of exploit-related heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • app.addToolButton/removeToolButton — CVE-2014-0496 critical CVE exact CVE_2014_0496
    PDF JavaScript combines app.addToolButton() and app.removeToolButton() with heap-spray shellcode markers — the public Adobe Reader/Acrobat ToolButton use-after-free exploit shape for CVE-2014-0496. (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.
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • 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://tritylod.onerate.mobi/world/safe_tighten_conquer-downstairs.txt?e=9
    • http://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/2.8/
    • http://www.xfa.org/schema/xfa-template/2.5/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0003_000.js
abf2429276374afae737bb027b914408118a8c8a6051b777ec09ebb3a4b13a19
pdf-javascript-stream PDF /JS object 3 at offset 0x409 15514 bytes
base26_stage_000.js
2450b0b933f6d68582a70cafc18996e458498b086b787d0530744f8e517186f3
deobfuscated-js base26-decoded JavaScript (decompressed) at offset 0x60D 5907 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 44 eval/decoder/string-building token(s).