Malicious PDF — malware analysis report

Static analysis result for SHA-256 1837e90f228521d7…

MALICIOUS

PDF

19.7 KB Authoring application: .132.141.72.156.133.148.141.130.147.136.142.141.63.126.104.82.71.126.104.80.72.154.145.132.147.92.70.70.90.133.142.145.71.136.92.79.90.136.91.126.104.80.77.139.132.141.134.147.135.90.136.74.92.81.72.1 (via .126.104.84.156.133.148.141.130.147.136.142.141.63.126.137.82.71.72.154.126.137.83.92.126.139.84.71.72.90.136.133.71.126.137.83.91.88.79.79.79.72.154.126.137.84.92.70.142.74.148.96.114.137.134.134.134)
MD5: 008866b9d9c0b89e201ebe328f9a37a6 SHA-1: 5344b17c57150c9340273464308b60535109dabb SHA-256: 1837e90f228521d7b3f07c188afc5de9843f2c788156f2358f2cbf53f641036b
98 Risk Score

Malware Insights

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

The PDF contains XFA forms with executable scripts, a common technique for exploiting PDF viewers. The ML classifier strongly indicates maliciousness. The embedded files are likely payloads or further stages of the attack, though their specific function cannot be determined from static analysis alone.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • 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.
  • 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
  • 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
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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://www.xfa.org/schema/xfa-locale-set/2.1/
    • http://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/1.0/
    • http://www.xfa.org/schema/xfa-template/2.2/
    • http://www.xfa.org/schema/xfa-data/1.0/

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin
c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
pdf-embedded-file PDF EmbeddedFile object 41 at offset 0x3B21 85 bytes
embedded_file_obj0042.bin
b40a217a8d9b8d3671cc3874c550d30941b93ca6dde99995d43921dede579865
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x3BD3 1183 bytes
embedded_file_obj0043.bin
931108dda7cc7bb198b2355eb58e1b47ce765477b1dfc1ae7b8ab76c8b202c29
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x3E23 1770 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0044.bin
3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x4216 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x42C2 77 bytes
font_00_cff_off000043d6.bin
062eede2d0cc5d3972869dc7e2f2f9f01d1d1b3756b715c8252f06948ce99ae2
pdf-font-stream PDF embedded font (cff) at offset 0x43D6 1192 bytes