Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f51dbce854ebca3…

MALICIOUS

PDF

23.0 KB Authoring application: 52-164-161-159-117-154-147-164-117-161-150-151-90-145-123-105-144-145-123-106-91-109-175-164-151-166-167-164-160-82-145-123-103-175-152-167-160-149-166-155-161-160-82-145-123-107-90-145-123-104-91-173 (via 1-154-119-162-107-152-161-116-125-97-97-97-97-97-169-115-115-115-115-116-115-115-115-115-115-115-115-115-115-115-115-115-131-115-115-115-115-115-115-115-115-139-170-117-115-133-155-115-153-139-115-97-)
MD5: 9a882872a9aaa8ec33064102b566dd93 SHA-1: ccfb5d3d58bfb4dc71f758840d510e6258a57018 SHA-256: 6f51dbce854ebca3a22c0e64ea6906c7ca71c5e916f8f3291fb287d7b85099cf
214 Risk Score

Malware Insights

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

The PDF file contains XFA forms with executable scripts, flagged by multiple heuristics as malicious. The 'PDF_EVAL' and 'PDF_XFA_SCRIPT' firings indicate that JavaScript code is being executed within the PDF, likely to download and execute a secondary payload. The ClamAV detection of 'Pdf.Exploit.Agent-36962' further confirms its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 10

  • 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.
  • ClamAV: Pdf.Exploit.Agent-36962 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36962
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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)
  • 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.
  • 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.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • 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/
    • 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 0x38CD 85 bytes
embedded_file_obj0042.bin
b40a217a8d9b8d3671cc3874c550d30941b93ca6dde99995d43921dede579865
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x397F 1183 bytes
embedded_file_obj0043.bin
31a7e179295d53a52ba690c5482cae457a4ff94ebdbb353a313bc09b352487eb
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x3BCF 1709 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
embedded_file_obj0044.bin
3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x3F75 144 bytes
embedded_file_obj0045.bin
ce4a3f07835c725838e55947d6b1f21771e0ad8084ee86d0890ecc12bd5231fd
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x4037 2427 bytes
font_00_cff_off00004407.bin
062eede2d0cc5d3972869dc7e2f2f9f01d1d1b3756b715c8252f06948ce99ae2
pdf-font-stream PDF embedded font (cff) at offset 0x4407 1192 bytes