Malicious PDF — malware analysis report

Static analysis result for SHA-256 881fa67849bf90ee…

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: 0a09ea61060fdcc9387b04bd193005bd SHA-1: df951c54ed1f89fc0b8da0ee6f2d1f44c31df3cc SHA-256: 881fa67849bf90ee949f95eb76175e521bf063df1763e3433621bb7e8ff610a6
166 Risk Score

Malware Insights

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

The PDF file was 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 commonly used to download and execute further malicious content. The presence of JavaScript actions and streams strongly suggests an attempt to exploit the user via a malicious attachment.

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
3acb53be7b4f8262feef02c54656746bfa8cd51b2493545856e947360816cf13
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 75175 bytes
Detection
ClamAV: Win.Trojan.Agent-36166
Obfuscation or payload: unlikely