Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4e5425d8ea2d673…

MALICIOUS

PDF

8.6 KB
MD5: 37e679fa9135b19e2bbe2de091295c00 SHA-1: 88baf052176582e2c89a288bb48479a771c4ded9 SHA-256: a4e5425d8ea2d6734b2b8e93e4cb241be743bbe0f1f60298f95d06f50e0c23cd
174 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File

This PDF sample utilizes XFA (XML Forms Architecture) with a heap spray exploit, indicated by the 'PDF_XFA_HEAP_SPRAY' and 'PDF_XFA_SCRIPT' heuristics. The embedded JavaScript is designed to execute a heap spray, a common technique for exploiting vulnerabilities. While the exact payload is not directly visible, the presence of an embedded URL suggests a downloader mechanism. The ML classifier strongly indicates maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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.
  • 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 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
  • 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
5aeadc6512b37ec5458f835e4dd4110d958bf3f5b1afd274d23108dd49081795
pdf-embedded-file PDF EmbeddedFile object 99999 at offset 0x1161 22500 bytes
embedded_file_obj0044.bin
3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x1D04 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x1DB1 77 bytes