Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf0827c808b1e237…

MALICIOUS

PDF

2.2 KB
MD5: 8c41d1e7d018cf1babd20a91111297cb SHA-1: ae20676b452acbaaa71ed2dad7167910eb50cd6d SHA-256: bf0827c808b1e237d676c658f5658e621fce35e73ca2999d4115ca87443054ac
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, PDF_EVAL, PDF_UNESCAPE, and PDF_FROMCHARCODE. The ClamAV detection 'Pdf.Exploit.Agent-36082' strongly suggests a known exploit. The JavaScript is obfuscated, making its exact function difficult to determine, but the presence of eval() and unescape() calls points to dynamic code execution, likely to download and run a secondary payload. The file's structure and heuristic firings align with common PDF-based exploit delivery mechanisms.

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 0x7D9 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
2a29b36bcc08f8492b7729573388233b257f2e79f813d1aeccfaa80c2d457fb0
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).