Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c244f2f251af1be…

MALICIOUS

PDF

51.6 KB Created: 2010-12-15 23:13:45 +02:00 Authoring application: Direct Payday Loan (via mPDF 5.0)
MD5: bdf1607bd457a987d8f9798d3dfdde4d SHA-1: da75dc041e215e11228ab3062902950aaca1f542 SHA-256: 9c244f2f251af1be25bb40898bb1cd841a04df67c39b872dc6ec7eee9136ebbd
106 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript streams, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The ML_NYX_PDF_MALICIOUS classifier strongly suggests malicious intent. The presence of unescape() calls and obfuscated scripts further supports this. The extracted JavaScript files, javascript_obj0034_000.js and javascript_obj0034_001.js, are likely responsible for executing malicious code, potentially downloading and executing second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

Heuristics 4

  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits
  • Suspicious extracted artifact medium 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.
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0034_000.js
357d06d70777f397a54fd04180a5ee36f36a8ec5c7cbbafdfab41f20901b25ac
pdf-javascript-stream PDF /JS object 34 at offset 0xC5E8 136 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long hex-escaped blob(s).
javascript_obj0034_001.js
607a0753f2d28ea7a383d2e729ee9a1eeb69db22eafb74fa3e1d444ae047c123
pdf-javascript-stream PDF /JS object 34 at offset 0xC5E8 134 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long hex-escaped blob(s).