Malicious PDF — malware analysis report

Static analysis result for SHA-256 9361decd03dcc3a6…

MALICIOUS

PDF

14.6 KB
MD5: a136500140be5d02dc64140a90c1030e SHA-1: 52ddef33446a120090e1ac8f3613528d2ed6447d SHA-256: 9361decd03dcc3a6b800461ceb854efcfc882e19faa0a7c0946050fc9dbbb0c0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 Command and Scripting Interpreter: PowerShell T1059.003 Command and Scripting Interpreter: Windows Command Shell T1204.002 Malicious Link: Malicious File

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as 'Pdf.Exploit.Dropped-94'. Static analysis revealed embedded JavaScript with obfuscation indicators, including the use of eval() and String.fromCharCode. This JavaScript is likely responsible for downloading and executing a second-stage payload, as indicated by the 'Suspicious extracted artifact' heuristic. No document body text was available for analysis, but the presence of obfuscated JavaScript strongly suggests a malicious intent to exploit vulnerabilities and compromise the user's system.

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 0x390F 144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).