Malicious PDF — malware analysis report

Static analysis result for SHA-256 39185e8a999ddfd7…

MALICIOUS

PDF

2.2 KB
MD5: cf52519a6ae44ef14f36e0a17f91b143 SHA-1: ec5f101e63300571909988d2266d5914be1f7f58 SHA-256: 39185e8a999ddfd7c99c97ad78019bab344f958b2797e13f2b83454ff2762286
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Script Execution T1566.002 Phishing: Spearphishing Attachment

The PDF file contains embedded JavaScript, including calls to eval() and unescape(), which are commonly used to obfuscate malicious code. A machine learning classifier and ClamAV also flagged this file as malicious, specifically identifying it as 'Pdf.Exploit.Agent-36082'. The presence of these indicators strongly suggests the PDF is designed to exploit vulnerabilities and deliver a malicious payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36082 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36082
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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.
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj111611_000.js
772da696bdb365f3f1eb4ea6af881baad391be62f3591b19f2f9827fcc4c9b53
pdf-javascript-stream PDF /JS object 111611 at offset 0x7DD 479 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
16e944c95c245d62972ff2651e3981ed7b0211cb13cd41a55ffc34880b8c855c
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2822 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).