Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c337f013c541fdc…

MALICIOUS

PDF

14.6 KB
MD5: 2c7bb35a66cfa4dd47be9aa68c7a182d SHA-1: 253190c3b504effd737b6ba14f30dead6aadbfa9 SHA-256: 7c337f013c541fdc38bd92495dbfa2bb9639bc9f48f5b14a1f45519c9845dc76
158 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 Scripting: JavaScript T1204.002 Malicious File: Malicious JavaScript

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as 'Pdf.Exploit.Dropped-94'. Static analysis revealed embedded JavaScript, including the use of `eval()` and `String.fromCharCode()`, indicating obfuscation. The JavaScript is likely responsible for executing an exploit and downloading a secondary payload, as suggested by the 'Suspicious extracted artifact' heuristic. No specific family could be identified.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • ClamAV: Pdf.Exploit.Dropped-94 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-94
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0076_000.js
c28effae366bd4b2a63fe29aea090a07947ae4e73aa9efc1cf87e16e006e7288
pdf-javascript-stream PDF /JS object 76 at offset 0x390C 144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).