Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4988eb98eac2044…

MALICIOUS

PDF

46.9 KB Created: 2011-04-12 19:13:42 -04:00 Authoring application: Writer (via 佰敮佦晩捥⹯牧′⸴㬠浯摩晩敤⁵獩湧⁩呥硴′⸱⸷⁢礠ㅔ㍘�)
MD5: 4a728a704b8d23c5d7f7ff40d717ebf5 SHA-1: fa5c04e4b8d9be0d0d8f2d246cebc029ed670cee SHA-256: a4988eb98eac20443d0b79a4841e7df738980d39af0dc68e2af25348980286d2
194 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.001 Command and Scripting Interpreter: PowerShell T1059.007 Command and Scripting Interpreter: JavaScript

The PDF contains critical XFA JavaScript heap-spray exploit code, indicating an attempt to execute arbitrary code. The presence of embedded files, including a larger one named 'embedded_file_obj0014.bin', suggests a downloader or dropper functionality. The unescape() and String.fromCharCode() calls further point to obfuscated script execution, likely to download and run a secondary payload.

Heuristics 10

  • XFA form contains risky executable script high CVE related PDF_XFA_SCRIPT
    PDF embeds an XFA form whose script block contains exploit, submission/launch, or shell-execution primitives. Ordinary LiveCycle print/update scripts are left as generic XFA/JS signals unless stronger behavior is present.
  • XFA JavaScript heap-spray exploit code critical PDF_XFA_HEAP_SPRAY
    PDF contains XFA script content with heap-spray or shellcode-like JavaScript markers such as large encoded word sequences, util.pack, large arrays, or spray variable names. This is a weaponised Adobe Reader exploit pattern, not a normal interactive form.
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules.
  • 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://www.monotype.comhttp://www.monotype.com/html/type/license.html
    • http://www.monotype.com/html/mtname/ms_timesnewroman.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlNOTIFICATION
    • http://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/1.0/
    • http://www.xfa.org/schema/xfa-template/2.5/
    • http://ns.adobe.com/xtd/
    • http://www.xfa.org/schema/xfa-data/1.0/
    • http://ns.adobe.com/xfdf/
    • http://www.xfa.org/schema/xfa-form/2.8/

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0012.bin
d81baa73e490e4cb879e13927cacd1dd1be37524a37eac51603e15117c578777		 pdf-embedded-file PDF EmbeddedFile object 12 at offset 0x7BBA 84 bytes
embedded_file_obj0013.bin
24c130f03a4cf51d470b536e94c1e58af67665739e200e0ce198ad41086243c0		 pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x7C51 228 bytes
embedded_file_obj0014.bin
45b624d9f1a8478eb8a52c63a5dcb658f7d4deb722962d8e56674ad2894f58f1		 pdf-embedded-file PDF EmbeddedFile object 14 at offset 0x7D7A 14270 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s). Carved artifact contains 7 long base64-like blob(s).
embedded_file_obj0015.bin
c97e0522381d6196cc0695f35f4d065f15c9c86a9601a7f776c6afd3f4c6b460		 pdf-embedded-file PDF EmbeddedFile object 15 at offset 0xB57B 199 bytes
embedded_file_obj0016.bin
846dfecc0c93797cb6db4301f6af323fffd76ffdf8c053c439495412785138e7		 pdf-embedded-file PDF EmbeddedFile object 16 at offset 0xB685 119 bytes
embedded_file_obj0017.bin
e6c26a3478346d27e841ad49868ebf68bf4c6863b6750e8d60bda3c4c6f79876		 pdf-embedded-file PDF EmbeddedFile object 17 at offset 0xB73E 77 bytes
embedded_file_obj0018.bin
92a3ce61d783e15932b5de127ce45a9b4c2f98f4da2453f65241573c1dda808a		 pdf-embedded-file PDF EmbeddedFile object 18 at offset 0xB7CD 56 bytes

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