Malicious PDF — malware analysis report

Static analysis result for SHA-256 d70f249365e3dacf…

MALICIOUS

PDF

118.6 KB
MD5: f718c0449b4500e323df445c71524bfb SHA-1: f754e26639b9208a4ae251be7f08f0c5398db1dd SHA-256: d70f249365e3dacfedebb7f95b35b18c16fe168fcc8f5db5a543cd7df8c56d54
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and a machine learning classifier. High-severity heuristics indicate the presence of JavaScript, including an eval() call and a large comment-padded JavaScript eval stager. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, as suggested by the 'ML_NYX_PDF_MALICIOUS' and 'PDF_JAVASCRIPT' firings. The document body was unreadable, but the technical indicators strongly suggest a malicious exploit delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36086 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Large comment-padded JavaScript eval stager high PDF_JS_LARGE_COMMENT_PADDED_EVAL
    PDF JavaScript contains a very large stream padded with long random-looking block comments around String.fromCharCode and eval. This is an exploit-kit obfuscation shape used to bury a decoder and recovered stage inside noise, not normal PDF form automation.
  • 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.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
ced49fd07a9c0ed5ab94fda9b10d3158969c25c753d8b80dd34b4044d7cb7747
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626125 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 42 long base64-like blob(s).