Malicious PDF — malware analysis report

Static analysis result for SHA-256 7355a15eda981e17…

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: 8f92a188d9146d75cf1857d6923bf3ff SHA-1: 5ad4c0d05018f87e298ae678f7e2f06e747f79a4 SHA-256: 7355a15eda981e171e48206443a1fdf09b7cdbc7d951b17ef24ca6942ae4b6c8
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Win.Trojan.Agent-36166. Embedded JavaScript was detected, which is likely used to download and execute a second-stage payload. The obfuscated JavaScript, while not fully decipherable, strongly suggests malicious intent consistent with a trojan downloader.

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
87f681efc40628e24d1ebfe8c08e39c5213ef58e97567a03957f1347deba5740
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 74414 bytes
Detection
ClamAV: Win.Trojan.Agent-36166
Obfuscation or payload: unlikely