Malicious PDF — malware analysis report

Static analysis result for SHA-256 71f36bafdc8798ed…

MALICIOUS

PDF

104.0 KB
MD5: 5efcad35188e8d6fd348c9e9d7ceb4d5 SHA-1: dbc5c00639c7af48aa8ef0000e8ecf726884d5e4 SHA-256: 71f36bafdc8798ed5b100ec9ff646e4dde2e99d296aad76162e2785cd08c3edb
268 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The PDF file contains XFA (XML Forms Architecture) which is known to be a vector for exploits. Heuristics indicate a heap spray exploit using JavaScript within the XFA form. This script is designed to download and execute a second-stage payload, as evidenced by the 'PDF_XFA_HEAP_SPRAY' and 'PDF_XFA_SCRIPT' firings. The embedded URLs are confirmed benign, and no other IOCs were extracted.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • 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
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • Embedded script payload in PDF stream low 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.
  • 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_0000023d.bin
af354a342980ec0cba4123ca89edee2a39f5824fbf030af5fdfe972a5dc995e6
pdf-embedded-script PDF raw stream script payload at offset 0x23D 105777 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36370
Obfuscation or payload: unlikely