Malicious PDF — malware analysis report

Static analysis result for SHA-256 288add48a7dd024a…

MALICIOUS

PDF

26.3 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode
MD5: 59894bce7c615d681abbb703163d33d8 SHA-1: f9ccb3779aea4ef14c0bd48601cab42ea6f24497 SHA-256: 288add48a7dd024a6d9c0e1524abb6396439f910b670de99aeb789f70ff841ac
66 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell: PowerShell

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The JavaScript stream, named 'javascript_obj0001_000.js', is likely responsible for executing malicious code. The use of String.fromCharCode and eval() suggests obfuscation, a common technique for evading detection. The primary function of the script appears to be downloading and executing a second-stage payload, although the exact URL or execution method is not directly extractable from the provided evidence.

Heuristics 5

  • 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_obj0001_000.js
47551df7a36d91a6521f999725498b913975bf85d20cedd06bb89f486c6f6760
pdf-javascript-stream PDF /JS object 1 at offset 0xA 955 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).