Malicious PDF — malware analysis report

Static analysis result for SHA-256 27b0b636ec4aa50d…

MALICIOUS

PDF

88.6 KB
MD5: e16a298c709f9959f191abbb104e1521 SHA-1: e71f14c718fe28933b12af38c6f24b510169dbc7 SHA-256: 27b0b636ec4aa50d502dbd258fcbdc3fcc49eeb791ea0db4f99f7a5b8f87fe45
244 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1204.002 Malicious File: User Execution: Malicious Attachment T1059 Command and Scripting Interpreter

The file is a PDF containing a critical XFA heap spray exploit, indicated by multiple high and critical heuristic firings. The embedded JavaScript and XFA script are likely used to execute arbitrary code. ClamAV detection further confirms its malicious nature. The primary attack vector appears to be exploiting a vulnerability within the PDF reader's handling of XFA forms.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • XFA form contains risky executable script high CVE related PDF_XFA_SCRIPT
    PDF embeds an XFA form whose script block contains exploit, submission/launch, or shell-execution primitives. Ordinary LiveCycle print/update scripts are left as generic XFA/JS signals unless stronger behavior is present.
  • XFA JavaScript heap-spray exploit code critical PDF_XFA_HEAP_SPRAY
    PDF contains XFA script content with heap-spray or shellcode-like JavaScript markers such as large encoded word sequences, util.pack, large arrays, or spray variable names. This is a weaponised Adobe Reader exploit pattern, not a normal interactive form.
  • ClamAV: Pdf.Exploit.Agent-6136306-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-6136306-0
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xfa-template/2.5/
    • http://www.xfa.org/schema/xfa-data/1.0/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_pdf_script_0000044d.bin
b3e585fb93711d665795df0ddac29f3a88f2e1f699c130cb6916c42c49b42967
pdf-embedded-script PDF raw stream script payload at offset 0x44D 89552 bytes