Malicious PDF — malware analysis report

Static analysis result for SHA-256 786b9fbaec3dad64…

MALICIOUS

PDF

8.7 KB
MD5: 31a160f762bdf0fa195c4b510a39714a SHA-1: 47eee0cf37b06768ba6b2a7d148d2dc5438588f7 SHA-256: 786b9fbaec3dad64588050057bf18ec18e53b6e9a533b0e99db40a82d79a4e8b
154 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File T1566.001 Phishing: Spearphishing Attachment

The PDF sample contains critical heuristic firings for XFA heap spray and risky executable scripts, indicating an exploit attempt. The ML classifier strongly supports a malicious verdict. The presence of an embedded URL suggests a potential download or redirection mechanism. The script's purpose is to trigger a heap spray exploit within the XFA form, which is a common technique for delivering further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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.
  • XFA JavaScript heap-spray exploit code critical PDF_XFA_HEAP_SPRAY
    PDF contains XFA script content with heap-spray or shellcode-like JavaScript markers such as large encoded word sequences, util.pack, large arrays, or spray variable names. This is a weaponised Adobe Reader exploit pattern, not a normal interactive form.
  • 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
  • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin
c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
pdf-embedded-file PDF EmbeddedFile object 41 at offset 0xE93 85 bytes
embedded_file_obj0042.bin
dda0835df994b8be920f715db36452f6cee7bb42bbc9c897f878a7b298ba8e91
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0xF45 1029 bytes
embedded_file_obj99999.bin
f7cc91e8390edf76313abdd0119189d9de11072585f854d47184b7db2a8999e7
pdf-embedded-file PDF EmbeddedFile object 99999 at offset 0x1161 21431 bytes
embedded_file_obj0044.bin
3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x1D5D 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x1E0A 77 bytes