Malicious PDF / .PHP — malware analysis report

Static analysis result for SHA-256 3858b4fb248b7d9e…

MALICIOUS

PDF / .PHP

15.0 KB Created: 2009-11-15 19:41:70 Authoring application: PDF Library 4.3.9 (via PDF Library 3.9.7)
MD5: f4c58c39d2dec1ca7d5829f6b9a5ea85 SHA-1: 464c3f83947b38686b3ee7a3a36496f3a214558b SHA-256: 3858b4fb248b7d9e2bed653755fef2a14988aefa3de7510450548cbef55a5938
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The file is identified as malicious by ML classifiers and ClamAV, which specifically detects it as Win.Trojan.Agent-36166. The presence of embedded JavaScript, indicated by PDF_JAVASCRIPT and PDF_JS heuristics, suggests an attempt to execute malicious code. This JavaScript likely functions as a downloader for further malicious activity, although its exact behavior is obscured by obfuscation. The primary IOC is the ClamAV detection signature.

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
d0e8ac4722636c4bc1aa208afb6b65ba102caf56264cb94b986f9ea8dfaca797
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 84111 bytes
Detection
ClamAV: Win.Trojan.Agent-36166
Obfuscation or payload: unlikely