Malicious PDF — malware analysis report

Static analysis result for SHA-256 66e1af93162aa081…

MALICIOUS

PDF

123.1 KB Created: 2009-03-05 21:22:26 +08:00 Authoring application: Acrobat Web Capture 8.0
MD5: 20fba7325b0dbb1409360ebcb8d6a3bb SHA-1: f664aaf02c7c3b46450482d3924d9ef2ed848594 SHA-256: 66e1af93162aa0818037e487d5fb1db5b268b294b23aced48e373edc478ae528
272 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF exploits CVE-2009-0658 using a JBIG2Decode filter and embedded JavaScript. The JavaScript code, specifically the unescape() calls, constructs shellcode that is likely intended to be executed by the exploit. The presence of multiple obfuscated JavaScript streams and the JBIG2 exploit strongly indicate a client-side execution attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 10

  • Adobe Reader JBIG2Decode generic heap-spray exploit critical CVE likely CVE_2009_0658_GENERIC_SPRAY
    PDF combines JBIG2Decode image streams with JavaScript heap-spray or decoder scaffolding. This is likely CVE-2009-0658-family Adobe Reader JBIG2 exploitation, but it lacks the stricter Reader-9 version gate or decoded page-word shellcode fingerprint required by the exact rule.
  • JBIG2 + active content high CVE related PDF_JBIG2_ACTIVE_CONTENT
    JBIG2Decode appears with JavaScript/XFA/RichMedia — a related indicator for JBIG2 parser-exploit families including CVE-2021-30860 and CVE-2009-0658, but not a unique CVE fingerprint.
  • 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)
  • JBIG2Decode filter medium PDF_JBIG2
    JBIG2 image decoder present — historically used in zero-click exploits
  • 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.
  • 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.
  • 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.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0054_000.js
76b9a9d595e071c01fab427db3229805067700ca8167c99a8d39a6f6869c3734
pdf-javascript-stream PDF /JS object 54 at offset 0x9495 867 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
javascript_obj0056_001.js
a286a724917c4ed12e23c56fdbe9b05a086df706402e840df93ca822a639bf8f
pdf-javascript-stream PDF /JS object 56 at offset 0xA650 867 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
javascript_obj0058_002.js
6300b36f22ef6578b0f03e4e9331a4dc1cfa3ef51cfced50c1ce2d725dd82351
pdf-javascript-stream PDF /JS object 58 at offset 0xB7B5 867 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
javascript_obj0060_003.js
9fdeb4cf92d3ba004fe834e1ec15e7554d02b14121596b2b2948628aa9003bc4
pdf-javascript-stream PDF /JS object 60 at offset 0xC848 868 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
stream_009_off00001c1f.bin
6a71966cad617bfb05c2fc57e09517130f7abf80fb7d2cd8d6f9a72dd0ff8cc6
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1C1F 8958 bytes
jbig2_00_off00008305.bin
f976667e94bad14883cbc6a8079f71823677caad2deab55c28b039c892f29152
pdf-jbig2-stream PDF JBIG2 stream at offset 0x8305 3739 bytes