Malicious PDF — malware analysis report

Static analysis result for SHA-256 943f8ce8e8b30fae…

MALICIOUS

PDF

22.6 KB Authoring application: 104-85-68-126-139-88-72-90-126-104-84-74-92-114-147-145-136-141-134-77-133-145-142-140-98-135-128-145-98-142-131-132-71-126-104-86-125-126-104-87-72-90-156-145-132-147-148-145-141-63-126-104-84-156-13 (via -156-132-139-146-132-154-126-137-84-92-70-138-97-74-96-114-137-136-112-135-100-143-88-133-142-97-106-78-78-78-78-78-150-96-96-96-96-97-96-96-96-96-96-96-96-96-96-96-96-96-112-96-96-96-96-96-96-96-96-1)
MD5: d68cb4d8fc61ce5e9b5d7b2471e83780 SHA-1: c93bb075e73a48af3b53a87dd4b2b309d1e1a15e SHA-256: 943f8ce8e8b30fae761d3b2fd47bb960233438fdbd774269c79d6201646be0ce
184 Risk Score

Malware Insights

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

This PDF file exhibits multiple high-severity heuristic firings, including 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' identifying it as 'Pdf.Exploit.Agent-36962'. The presence of XFA forms with risky executable scripts and embedded files strongly suggests an exploit attempt. The primary attack vector appears to be leveraging a PDF vulnerability to execute embedded scripts, which are likely designed to download and execute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 9

  • 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
  • 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
  • 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.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/

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 0x36CD 85 bytes
embedded_file_obj0042.bin
b40a217a8d9b8d3671cc3874c550d30941b93ca6dde99995d43921dede579865
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x377F 1183 bytes
embedded_file_obj0043.bin
abf64c787afd55dd1c99ba75b19d779fa14c2bb4eb682d88cd4080fc5ea1fa57
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x39CF 1917 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 0x3DC6 144 bytes
embedded_file_obj0045.bin
ce4a3f07835c725838e55947d6b1f21771e0ad8084ee86d0890ecc12bd5231fd
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x3E88 2427 bytes
font_00_cff_off00004258.bin
062eede2d0cc5d3972869dc7e2f2f9f01d1d1b3756b715c8252f06948ce99ae2
pdf-font-stream PDF embedded font (cff) at offset 0x4258 1192 bytes