Malicious PDF — malware analysis report

Static analysis result for SHA-256 03c156de86aaf33b…

MALICIOUS

PDF

45.9 KB
MD5: d6ec9788f2d3d08880735df6c2e7f691 SHA-1: 875cc68c9926d3425a4be13df8cfd76c867f2191 SHA-256: 03c156de86aaf33bcb5357a5d37f0f10fdf5b2194ede3c2d0793c425a003bad5
316 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript that leverages known vulnerabilities (CVE-2009-3459 and CVE-2009-3953) related to U3D content processing in Adobe Reader. The JavaScript is heavily obfuscated and appears to download and execute a second-stage payload. The ML classifier strongly indicates maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • Adobe Reader U3D auto-activated 3D annotation — CVE-2009-3459 critical CVE likely CVE_2009_3459_U3D_AUTOACTIVATE
    PDF contains a /Subtype /3D annotation that is configured to auto-activate on page view (/3DA <</A /PV /AIS /I>>) alongside a /U3D stream and JavaScript. This is the document shape used by CVE-2009-3459 (Adobe Reader U3D CLODProgressiveMeshDeclaration heap overflow, APSB09-15): the U3D parser runs without any user interaction once the page is rendered, while the accompanying JavaScript prepares a heap-spray to land controlled memory inside the corrupted allocation.
  • Adobe Reader U3D CLODProgressiveMeshDeclaration exploit critical CVE likely CVE_2009_3953
    PDF combines malformed U3D 3D content with JavaScript/action activation. CVE-2009-3953 is an Adobe Reader/Acrobat U3D CLODProgressiveMeshDeclaration array-boundary vulnerability triggered by malformed U3D data in a PDF.
  • U3D/3D content in PDF — Adobe Reader 3D parser CVE-family indicator high CVE related PDF_U3D_CVE_RELATED
    PDF contains U3D (Universal 3D) or 3D annotation content — CVE-2011-2462 and CVE-2009-3953 are critical vulnerabilities in Adobe Reader's U3D processing that allow arbitrary code execution. U3D content in PDFs is extremely rare in normal documents.
  • 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)
  • 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.
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0009_000.js
a071b43d5f5358ba43101f43a755162fbda66fc01f03fe7461cf777fdd16a7ae
pdf-javascript-stream PDF /JS object 9 at offset 0x48F3 469 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
b1a8ee2195b8fdb2f628dfb1e6577eea2747eeb1e1793e74c5bb514a0b28a8ef
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1D91 13004 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
5c3a4f59b911e13a09c00f154c7c3ac0f099da9f5d4590330799d7facc0d4104
deobfuscated-js PDF JavaScript deobfuscation pass 322184 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 2 long base64-like blob(s).
u3d_00_off00004b28.bin
fb27c6f6ffe2b08a88f79f344ef3cb4f85460ac81a062194b6fd84ab6e48b628
pdf-3d-stream PDF U3D 3D stream at offset 0x4B28 28021 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.79, consistent with packed or encrypted content.