Malicious PDF — malware analysis report

Static analysis result for SHA-256 f043f1f074f8ea54…

MALICIOUS

PDF

118.7 KB
MD5: df187916f8bf308292c7f5d33085d980 SHA-1: 5dec22f77c46298fc237e49e3d806ae7fd66fb89 SHA-256: f043f1f074f8ea5486d1b414209dee04a23b5c8db018ec59012dd6803413ec1a
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. The 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' heuristics, along with the 'Pdf.Exploit.Agent-36086' ClamAV detection, strongly suggest malicious intent. The embedded JavaScript is likely used to exploit a vulnerability within the PDF reader, leading to the execution of a malicious payload. The presence of a large comment-padded JavaScript eval stager further supports this. The document body is heavily obfuscated and unreadable, providing no direct clues to the lure.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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
6e75bdf472ce8143660c630a8a8c94672c8113e90fd3f436d88468fe6ef263c1
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626935 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).