Malicious PDF — malware analysis report

Static analysis result for SHA-256 576d6ebdef1ce822…

MALICIOUS

PDF

118.5 KB
MD5: f5b22c7b8d5881df30ed8eb6bf6925df SHA-1: b51f29c37068c4a00bd848ce364b62657bbe3590 SHA-256: 576d6ebdef1ce82277d1d06c8bebe4746e100fa2b0806901fbdfae2f4d6bb19a
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 strongly suggest malicious intent, with ClamAV identifying it as 'Pdf.Exploit.Agent-36086'. The presence of 'eval()' and 'String.fromCharCode' within the JavaScript stream points to obfuscation techniques used to hide the execution of malicious code, likely a second-stage payload.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
e4e481e3188731b3a22b98ab4a5b902e686e16ae6071a2d6c5cd31eaa30a7138
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626800 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).
legacy_pdfkit_stage_000.js
950d8dec98f58287ac3caa60a0f22c9e49e7754670b0afd10619d099fbaf8549
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 614 long base64-like blob(s).