Malicious PDF — malware analysis report

Static analysis result for SHA-256 c155b8316e18a5a5…

MALICIOUS

PDF

19.2 KB
MD5: 02d3a0d24c0e1decaff7ce1c4016c504 SHA-1: 5c70288d0330a4efd5ec3b7b15443d03cef8768e SHA-256: c155b8316e18a5a5e31d907d244ebd75d79f245e2e890bd65fb1f28c280fe453
126 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1566.002 Spearphishing Attachment

The file is identified as malicious by multiple heuristics, including a critical ClamAV detection (Pdf.Exploit.Dropped-78) and a high ML classifier score. The presence of an embedded script payload and an embedded file suggests the PDF is designed to exploit vulnerabilities and download or execute a second-stage payload. The XFA form structure is also noted, which can sometimes be leveraged for exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • ClamAV: Pdf.Exploit.Dropped-78 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-78
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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_file_obj0008.bin
07d6a7d5577031e1142657a8d6a9396a6862e52b42e0a0ec247c074e7712495a
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xC8 18870 bytes