Malicious PDF — malware analysis report

Static analysis result for SHA-256 04cbc85ce53a7559…

MALICIOUS

PDF

37.7 KB
MD5: d60f3838c517696a89e1cc7edac85138 SHA-1: c8d0b04531d9ef89a3b870b9fff2d3f40fb8fb9d SHA-256: 04cbc85ce53a755914415adc312237a3ebea9dac12c5432ab2ee83e48734b5e0
186 Risk Score

Malware Insights

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

The sample is a PDF file that contains embedded JavaScript, identified by multiple heuristics including 'PDF_JAVASCRIPT' and 'PDF_JS_EXPLOIT_CLUSTER'. The embedded JavaScript is heavily obfuscated but appears to construct a URL from concatenated strings. This script is designed to download and execute a second-stage payload, likely from the domain 'www.flashandmath.com'. The presence of 'PDF_RICHMEDIA' suggests potential Flash exploitation, further indicating a multi-stage attack. The overall confidence is high due to the ML classifier and multiple exploit-related heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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.
  • 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
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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. (matched inside decoded stream)
  • 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
    • 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/xap/1.0/sType/ResourceRef#
    • http://adobe.com/AS3/2006/builtin

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
a3befcc4b53c20d5df89b05c82de738c37f2e6825eefc40e007f674633113e60		 pdf-javascript-stream PDF /JS object 6 at offset 0xF5 1570 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).

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