Malicious PDF — malware analysis report

Static analysis result for SHA-256 67921dff06949c85…

MALICIOUS

PDF

14.4 KB Created: 2009-11-15 19:41:70 Authoring application: PDF Library 4.3.9 (via PDF Library 3.9.7)
MD5: 179e61b1a69632114677b735a3f9e4ca SHA-1: 325069bd4d89384dbcc853248dcaa4444998133f SHA-256: 67921dff06949c853e9faf5afd7d4b95476dd1dc7da825a517cf9fbe3bf88fa8
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is a PDF containing embedded JavaScript, flagged by multiple heuristics and a machine learning classifier as malicious. ClamAV identifies it as Win.Trojan.Agent-36166. The embedded JavaScript is heavily obfuscated but appears to be designed to download and execute a second-stage payload, a common technique for malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • ClamAV: Win.Trojan.Agent-36166 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36166
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
2ad54a24f1f25d532f1dc869c80198fd6d68bc6e54781ded883dd4b0ca906e6c
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 74579 bytes
Detection
ClamAV: Win.Trojan.Agent-36166
Obfuscation or payload: unlikely