Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef7ae4468ca1e1e6…

MALICIOUS

PDF

18.3 KB
MD5: 1835f6d110f62d5cf288163b99b47158 SHA-1: bdd82ef1c90e5aaed44ff0a7314ef8a0ee40600e SHA-256: ef7ae4468ca1e1e6b7634bc286d05286605cff2e9bdb6c4ff3c8e7467f3dad44
164 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1059 Command and Scripting Interpreter

The PDF sample was flagged by ClamAV as Pdf.Exploit.Agent-36928 and a machine learning classifier indicated a high probability of maliciousness. The presence of an XFA form with executable script (PDF_XFA_SCRIPT) and an embedded file (PDF_EMBEDDED) strongly suggests the document is designed to exploit a vulnerability. The embedded URL, while seemingly benign, is present within the document structure and could be part of a larger exploit chain. The primary attack vector appears to be leveraging the XFA scripting engine to execute arbitrary code.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • 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-36928 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36928
  • 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin
c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
pdf-embedded-file PDF EmbeddedFile object 41 at offset 0x3AB7 85 bytes
embedded_file_obj0042.bin
dda0835df994b8be920f715db36452f6cee7bb42bbc9c897f878a7b298ba8e91
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x3B69 1029 bytes
embedded_file_obj0043.bin
ba0e5e9325a205dc6ca244a8d3585dd8bcaf7a9184a56f9d93dfa48724da36ce
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x3D82 1645 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 0x4137 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x41E3 77 bytes