Malicious PDF — malware analysis report

Static analysis result for SHA-256 397a3dc0543fe0d3…

MALICIOUS

PDF

2.2 KB
MD5: eb8dd2f7569a1a9d0ebf913318045216 SHA-1: 002610f1bd8d66c2bd97150a3ccb25a912baa902 SHA-256: 397a3dc0543fe0d39072cac3375c9b9bd03c38ebb2d8ccc87d6e558b65d5ae46
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1027 Obfuscated Files or Information

This PDF file was flagged by ClamAV as Pdf.Exploit.Agent-36082. Static analysis revealed embedded JavaScript with high-confidence indicators of malicious activity, including eval() and unescape() calls, and String.fromCharCode usage, suggesting obfuscation. The ML classifier also strongly indicated maliciousness. The primary intent appears to be the execution of obfuscated JavaScript, likely to download and execute a secondary payload, which is a common technique for PDF-based malware delivery.

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 0x7DA 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
17044dc657a0c05b46b83343563fa907b527d5474078a738284004a2986c7910
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).