Malicious PDF — malware analysis report

Static analysis result for SHA-256 169d19a4394cbd6b…

MALICIOUS

PDF

102.8 KB Created: 2008-03-03 17:06:20 +08:00 Authoring application: Advanced PDF Repair: http://www.pdf-repair.com
MD5: c4eb113d494d5b30aa1f3b8d48789642 SHA-1: 8804d0316a2ff0635660f8f4f37ad127d4de822e SHA-256: 169d19a4394cbd6b48cc5bafba32a639722c20ac89cd4a972c7569aeba3548c4
228 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript with eval() calls, a known indicator of malicious activity. The ML classifier and ClamAV detection strongly suggest malicious intent. The JavaScript is obfuscated, but the presence of eval() and the PDF exploit cluster heuristics indicate it's designed to execute arbitrary code, likely downloading a second-stage payload. The file's origin as a PDF with embedded scripts points to a spearphishing attachment delivery method.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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.
  • ClamAV: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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
  • 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.pdf-repair.com
    • http://www.pdf-repair.com)/Producer(Advanced
    • http://www.pdf-repair.com)/ModDate(D:20100404092506+08
    • http://www.pdf-repair.com)/ModDate(D:20100404093132+08
    • http://www.pdf-repair.com)/ModDate(D:20100404093243+08
    • http://www.pdf-repair.com)/ModDate(D:20100404093525+08
    • http://www.pdf-repair.com)/ModDate(D:20100404093601+08
    • http://www.pdf-repair.com)/ModDate(D:20100404094947+08
    • http://www.pdf-repair.com)/ModDate(D:20100404095117+08
    • http://www.w3.org/1999/xhtml
    • http://www.xfa.org/schema/xfa-data/1.0/
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://purl.org/dc/elements/1.1/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0054_000.js
2fe85b93fb9b41eb8a33b9e59056e1b5da436c9a40c19deb91141a24d573bd72
pdf-javascript-stream PDF /JS object 54 at offset 0x1805A 18211 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).