Malicious PDF — malware analysis report

Static analysis result for SHA-256 a914f17e5ea5ec39…

MALICIOUS

PDF

15.7 KB
MD5: 39acc4cdeec6b592e74f97ade88f6bcc SHA-1: 427d009ab07592ab6da01329eec2872cf4bfe0cf SHA-256: a914f17e5ea5ec39bce16d13e7f608910b6a61c9cc535f3b01e41a8f843e9c59
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. A critical ClamAV detection (Pdf.Exploit.Agent-36086) further confirms its malicious nature. The JavaScript stream, identified as 'javascript_obj0006_000.js', is heavily obfuscated and likely functions as a stager to download and execute a secondary payload. The presence of eval() and fromCharCode functions within the JavaScript stream points to dynamic code execution, a common technique for malware delivery.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36086 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Large comment-padded JavaScript eval stager high PDF_JS_LARGE_COMMENT_PADDED_EVAL
    PDF JavaScript contains a very large stream padded with long random-looking block comments around String.fromCharCode and eval. This is an exploit-kit obfuscation shape used to bury a decoder and recovered stage inside noise, not normal PDF form automation.
  • 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. (matched inside decoded stream)
  • 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_obj0006_000.js
0779c0efed33c61fde0981bb2fbc17fbe5eb2b598a420bd8b59bf45f2c7832f6
pdf-javascript-stream PDF /JS object 6 at offset 0x143 424623 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 42 long base64-like blob(s).