PDF malware analysis — malicious · b8163a952923132f

MALICIOUS

PDF

91.1 KB Created: 2010-06-29 10:30:35 +08:00 Authoring application: Acrobat 编辑器 8.0 (via Adobe Acrobat 8.0) First seen: 2022-03-20

MD5: 2dd7f04b006821eba4369794e74fdba7 SHA-1: 2b4f2664c183860e63606620d711dd7382a72cfd SHA-256: b8163a952923132f8c9e609a73dfbe249d55dacd142ce83b578afbef43e93ca5

460 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell T1204.002 Malicious File

The PDF contains embedded JavaScript that exploits CVE-2009-4324 using the media.newPlayer API. This JavaScript is designed to download and execute a secondary payload, as indicated by the 'unescape()' call and the presence of an embedded, suspicious secondary PDF. The polyglot nature of the file suggests a multi-stage attack. No specific family could be identified.

Machine Learning

Nyx PDF Classifier malicious score 0.9987

Heuristics 13

Adobe Flash Player RichMedia exploit critical CVE likely CVE_2011_0611_FLASH_RICHMEDIA

PDF combines RichMedia Flash activation with an embedded AS3 SWF loader (ByteArray/loadBytes) and shellcode heap-spray staging. This is the static exploit shape associated with CVE-2011-0611 Flash content delivered through Adobe Reader.
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)
Flash ActionScript-3 exploit loader in PDF critical CVE related PDF_FLASH_AS3_EXPLOIT_LOADER

An embedded Flash (SWF) object's ActionScript-3 bytecode contains exploit-loader primitives: decompressing an inner SWF into a ByteArray and executing it via LoaderContext.allowLoadBytesCodeExecution, and/or Vector heap/JIT spray groomers. Benign Flash content does not load and execute code from raw bytes — this is a staged Flash exploit delivered through the document.
Secondary embedded PDF body has suspicious static findings critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE

A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
JavaScript action low 2 related findings PDF_JAVASCRIPT

PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
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.
Matched line in script
```
 var nop =  unescape("\x25\x750c0c");
```
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. (matched inside decoded stream)
RichMedia (Flash) high PDF_RICHMEDIA

PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector (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.
Embedded file low PDF_EMBEDDED

PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload (matched inside decoded stream)
PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE

PDF has 1 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.
Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL

The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
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://www.w3.org/1999/02/22-rdf-syntax-ns# In PDF document text
- http://ns.adobe.com/xap/1.0/In PDF document text
- http://purl.org/dc/elements/1.1/In PDF document text
- http://ns.adobe.com/xap/1.0/mm/In PDF document text
- http://ns.adobe.com/pdf/1.3/In PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`stream_002_off00000392.bin`	decompressed-pdf-stream	PDF FlateDecoded stream at offset 0x392	4264 bytes
SHA-256: `dc7871b301d6502b20da5da1fb4bce7526393149933b7cc9d92a16bc6c19e183`
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 3 long base64-like blob(s). Carved artifact contains 1 long hex-escaped blob(s).
`legacy_pdfkit_stage_000.js`	deobfuscated-js	string-concatenation normalized Acrobat API aliases at offset 0x392	126 bytes
SHA-256: `42c3f4df375ff6f58ff655cc4f88b5cc28f0dd33b978390db3538684a6219b74`
Preview script First 1,000 lines of the extracted script media.newPlayer(null); /* AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA */
`objstm_0017_00.bin`	pdf-objstm-decoded	PDF /ObjStm 17 0 obj (inflated)	871 bytes
SHA-256: `dd7918c182d6e2b8d996a6b8ee81663c49a0cb297efe1e1fa3c5af0c987bde84`
`polyglot_child_pdf_off00013a6b.pdf`	polyglot-child-pdf	Secondary PDF body inside pdf container at offset 0x13A6B	12786 bytes
SHA-256: `c11e03ac3120cdf0cd05eece897322e896c303597d3fb0ca37da9cb3fa4f3e07`
`polyglot_child_pdf_off00015470.pdf`	polyglot-child-pdf	Secondary PDF body inside pdf container at offset 0x15470	6125 bytes
SHA-256: `0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8`

Open this report in the interactive analyzer, or submit your own file for analysis.

PDF

Malware Insights

Machine Learning

Heuristics 13

Related samples 8

Extracted artifacts 5