Malicious PDF — malware analysis report

Static analysis result for SHA-256 08b872e9afd1437a…

MALICIOUS

PDF

54.9 KB
MD5: a1d560f024b5e5839f828e6dd80cb401 SHA-1: b038e099c6f93324d044fa152c41a17f8be6ade7 SHA-256: 08b872e9afd1437a1a78c56e39063fa21d4209e360bb1736eb1d617c767bb446
194 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript and a Flash object (Adobe.swf), both of which are commonly used to deliver exploits. The JavaScript uses String.fromCharCode and concatenation to obfuscate its content, but the heuristics indicate it's part of an exploit cluster. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, a common technique for malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 10

  • 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
  • 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. (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://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/2.6/
    • http://www.xfa.org/schema/xfa-template/2.6/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Adobe.swf
a6e35bb53095157439b80f291d74b0a64117a3eac9c696a5d9556fcc9a915f04
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0xE41 45209 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.
javascript_obj0006_000.js
ac94e851635343c63f586e4860c810310c6c819615acb5d9f387820b78a4fd6e
pdf-javascript-stream PDF /JS object 6 at offset 0x105 10494 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).