Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3a42dae5a5f4421…

MALICIOUS

PDF

14.3 KB Created: 2009-11-15 19:41:70 Authoring application: PDF Library 4.3.9 (via PDF Library 3.9.7)
MD5: feaab9cbab94f67c4b59c00f91a09bfb SHA-1: 4ad135b5b9cd010ba4a067acf547147fefb88ded SHA-256: b3a42dae5a5f4421bdf8adf58cc5ed72f76a16d94019bf00a9123233966e3bd6
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF file was flagged as malicious by multiple heuristics, including a critical ClamAV detection identifying 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 upon opening the document. The ML classifier also strongly indicated maliciousness. The primary IOC is the ClamAV detection name.

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
1a2ba5eda0b955786f95d1df9b7bd038d61aef795c302338a73db6ef38240f19
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 74602 bytes
Detection
ClamAV: Win.Trojan.Agent-36166
Obfuscation or payload: unlikely