Malicious PDF — malware analysis report

Static analysis result for SHA-256 99bf7e063835b118…

MALICIOUS

PDF

152.5 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: 2013-07-01
MD5: 33d57a3fe8d831adbbcd1aa81a62c21f SHA-1: 15ca5c4ed58720636c6e5d4f0ea09b2ea70864c7 SHA-256: 99bf7e063835b118189a46bb4d607e1eb4ec656dea69e9533fd197ee8b8a10f1
458 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious Link

The PDF file contains embedded JavaScript and is flagged for exploiting CVE-2009-4324, a vulnerability related to media player handling. This indicates the file is designed to execute malicious code upon opening. The presence of an embedded secondary PDF and JavaScript streams further supports the conclusion that this is a multi-stage attack, likely intended to download and execute additional malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8235

Heuristics 12

  • 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)
  • 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.

FilenameKindSourceSize
stream_002_off00000392.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x392 4264 bytes
SHA-256: 66f925b3dd9fded19643d178bfb48a158a3c1367dec432097a0b2a2d0cd77fde
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_off0002088b.pdf polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x2088B 22951 bytes
SHA-256: 9d7f32e1d3e9fe2225f0e8b1b61b2187d79d9e5bedd01f305eca13dd6725062d
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).
polyglot_child_pdf_off00024a45.pdf polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x24A45 6125 bytes
SHA-256: 0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8