Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b1b09a78b2e2ea4…

MALICIOUS

PDF

11.7 KB
MD5: c5ab02931a42a7587f40718e8c8d1797 SHA-1: 8f820ca28c99a988d6c82286d6061e96d941c255 SHA-256: 1b1b09a78b2e2ea4a7b1da8b7e75dfcfb18144544d706bd294a6c88ec2ae0fc3
126 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier with a high probability of being malicious and was also detected by ClamAV as Pdf.Exploit.Dropped-78. The presence of an embedded script payload and an embedded file indicates an attempt to deliver a secondary exploit or malware. 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
517493091a946d29110f4e540b41ff98728dd7016f5e9ba0356d32cb040b8c71
pdf-embedded-file PDF EmbeddedFile object 8 at offset 0xC8 11205 bytes