Malicious PDF — malware analysis report

Static analysis result for SHA-256 d151132dc2b177b8…

MALICIOUS

PDF

26.7 KB Created: 2011-10-06 11:19:19 +03:00 Authoring application: Wiki Farm Land Loans (via mPDF 5.0)
MD5: c2180b83e2e97bd97612cf2a211d0866 SHA-1: 6f26318cd26b0e17efea6442ced0f062f07c82cc SHA-256: d151132dc2b177b869ff7dd354bcc48aaf2c5bd2f949a57dc22a766ea0383942
106 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell T1566.002 Spearphishing Attachment

The PDF contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. The ML classifier strongly flagged this PDF as malicious. The extracted artifacts, javascript_obj0020_000.js and javascript_obj0020_001.js, show signs of obfuscation, suggesting they are designed to download and execute a second-stage payload. The presence of unescape() calls further supports the obfuscation technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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_obj0020_000.js
357d06d70777f397a54fd04180a5ee36f36a8ec5c7cbbafdfab41f20901b25ac
pdf-javascript-stream PDF /JS object 20 at offset 0x63FD 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_obj0020_001.js
607a0753f2d28ea7a383d2e729ee9a1eeb69db22eafb74fa3e1d444ae047c123
pdf-javascript-stream PDF /JS object 20 at offset 0x63FD 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).