Malicious PDF — malware analysis report

Static analysis result for SHA-256 013524bc8bf265f9…

MALICIOUS

PDF

43.5 KB
MD5: a576e219896eb11fb4bb79f5215fe0e0 SHA-1: 58f87fa2cf7e08a692b6c628be90c1eebaf4aa92 SHA-256: 013524bc8bf265f90a4799a74c2ad22e02241f150208c9c17045be6a12f05036
296 Risk Score

Malware Insights

MITRE ATT&CK
T1190 Exploit Public-Facing Application

The PDF file contains multiple critical heuristic firings indicating exploitation of Adobe Reader vulnerabilities related to U3D content (CVE-2009-3459 and CVE-2009-3953). Embedded JavaScript is obfuscated and appears to be a dropper, designed to decode a payload from the annotation subject and execute it. 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.
  • Generic recovered JavaScript exploit stage high PDF_GENERIC_STAGE_RECOVERY
    Bounded static stage recovery exposed hidden JavaScript through generic transforms such as null-byte collapse, percent decoding, marker replacement, arithmetic character codes, fromCharCode, numeric arrays, numeric-array minus-key decoders, alphabet-index arrays, /Producer half-difference metadata arrays, hex literals, marker-stripped Base64 literals, custom 6-bit XOR table decoders, or repeated-marker hex carriers. This rule is emitted only when the recovered stage contains exploit-like Acrobat JavaScript or shellcode markers.
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 3 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_dashed_payload, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
  • 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 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
71f6881f7016ac071115207cf6f8d643d210cc9cf8198fe32f636ce385fec006
pdf-javascript-stream PDF /JS object 5 at offset 0x14F 766 bytes
generic_stage_recovery_000.js
07901a728032d0654be19081ccc6641aaf76007322117e89820ec204416dd713
deobfuscated-js generic stage recovery split-literal-normalize from JavaScript object 5 at offset 0x14F 763 bytes
legacy_pdfkit_stage_000.js
d5c98dab75f1d8fbe9b7be3c0e8fc05749c103789345f6b79003d20be9046008
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1C53 13104 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
ea3c2f767f6725e8f0668e660eb7b739522edfe58182dcd9efd3769a2b7096c6
deobfuscated-js nested inline base-23 callee-key decoded JavaScript at offset 0x1C53 5228 bytes
deobfuscated.js
027a24befc24e8314af6375d5da336d9df8ec2e0daf23a4e890a37ed8094c04c
deobfuscated-js PDF JavaScript deobfuscation pass 207806 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
u3d_00_off000041ed.bin
fb27c6f6ffe2b08a88f79f344ef3cb4f85460ac81a062194b6fd84ab6e48b628
pdf-3d-stream PDF U3D 3D stream at offset 0x41ED 28021 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.79, consistent with packed or encrypted content.