Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1aec5c26563cba9…

MALICIOUS

PDF

2.2 KB
MD5: bce575a70f9ba8beee0740ed82379392 SHA-1: 82d5afd31d2376bac772260a6bdff3e997752589 SHA-256: c1aec5c26563cba9070c7890635a2a97d865178f447c64a9367230974ac9e819
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1027 Obfuscated Files or Information

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. The JavaScript is heavily obfuscated using eval() and unescape() functions, making its exact behavior difficult to ascertain without dynamic analysis. However, the presence of these obfuscation techniques and the ClamAV detection of 'Pdf.Exploit.Agent-36098' strongly suggest malicious intent, likely involving the execution of a second-stage payload.

Heuristics 7

  • ClamAV: Pdf.Exploit.Agent-36098 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36098
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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. (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_obj111611_000.js
e1ab3bbf30605cecdce6db9d2556198626dbb178f7a4cb471a9436bb6e8bd92f
pdf-javascript-stream PDF /JS object 111611 at offset 0x78D 462 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
bfbc87ab8f45e10315a1b2e53cae68d90404ff11dda6b35e5c38500eff85103e
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2822 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).