Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f97517abc4550e2…

MALICIOUS

PDF

14.5 KB Created: 2009-11-15 19:41:70 Authoring application: PDF Library 4.3.9 (via PDF Library 3.9.7)
MD5: f6c85928366a3501e6124dc6ab8aecdf SHA-1: 6f496e9edbfc7d8348543bec1987ee90243bcddb SHA-256: 5f97517abc4550e23b98d02e74960f04c03f9d0bba9b93c998c44077b7fa2f2f
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 obfuscated JavaScript, flagged by multiple heuristics and a machine learning classifier as malicious. ClamAV identifies it as Win.Trojan.Agent-36166, indicating it likely functions as a trojan downloader. The JavaScript is heavily obfuscated, but its presence and the PDF format strongly suggest an exploit targeting PDF viewers to download and execute a secondary payload.

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
ebbcbb006f3bc48f125aa150469f3ac6299768ceb6bdb17722ffada15789b65c
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 74800 bytes
Detection
ClamAV: Win.Trojan.Agent-36166
Obfuscation or payload: unlikely