Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd7efeb280993120…

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: 218c7f0bb97d9818a44fa24da61bb490 SHA-1: 4f1b3b75ccf86fb72d84336bf333b1364849caa4 SHA-256: cd7efeb280993120f93e8ce8efbdf4cea1ac6772783c37a84e1c04c118df5602
106 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious File T1059.001 PowerShell

The PDF file contains XFA form elements with executable scripts, a known technique for exploiting PDF vulnerabilities. The ML classifier strongly indicates maliciousness. The presence of embedded files and a URL suggests a delivery mechanism for a secondary payload. No specific script content was readable to determine its exact function, hence the confidence is not higher.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • 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
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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/

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 0x39D3 85 bytes
embedded_file_obj0042.bin
b40a217a8d9b8d3671cc3874c550d30941b93ca6dde99995d43921dede579865
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x3A85 1183 bytes
embedded_file_obj0043.bin
7603a3f3555a44eccaa71e4b2011b76cd9a84809b906d7f87e085ee82c67299d
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x3CD5 1719 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 0x40AB 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x4157 77 bytes
font_00_cff_off0000426b.bin
062eede2d0cc5d3972869dc7e2f2f9f01d1d1b3756b715c8252f06948ce99ae2
pdf-font-stream PDF embedded font (cff) at offset 0x426B 1192 bytes