Malicious PDF — malware analysis report

Static analysis result for SHA-256 631dc453339c49ed…

MALICIOUS

PDF

93.3 KB
MD5: 6af7b904c3079e149e2ee29ac33cbb2b SHA-1: a6683b114396fc6ba092b0e89474d47e1ff76619 SHA-256: 631dc453339c49ed0b48a74ea516634e1c4543adf550f4448af180321133bc52
168 Risk Score

Malware Insights

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

The PDF utilizes XFA (XML Forms Architecture) and contains embedded JavaScript, as indicated by the PDF_XFA and PDF_EMBEDDED_SCRIPT_PAYLOAD heuristics. The embedded script is heavily obfuscated but appears to be designed to download and execute a secondary payload. The ML classifier and ClamAV detections strongly support its malicious nature, classifying it as an exploit agent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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_00000246.bin
2a8c7f317a601a1fb3ca8e046ed78118658ab737f7409790fceb6ec4b3e30e25
pdf-embedded-script PDF raw stream script payload at offset 0x246 94820 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36769
Obfuscation or payload: unlikely