Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bd9ca7c571ac91f…

MALICIOUS

PDF

14.0 KB First seen: 2026-05-08
MD5: 6a7d025839f75dd4c59d4954ce75d1f0 SHA-1: ac8dbb3c642de3951042e617141ea50b0c4923a6 SHA-256: 4bd9ca7c571ac91f3542d596b9718baae4408caef517edb68fc2bf2eb81ba238
140 Risk Score

Malware Insights

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

The PDF file exhibits multiple indicators of malicious intent, including embedded files and an XFA form, which are often used to disguise or deliver secondary payloads. The presence of an embedded script payload further supports this, indicating the document is designed to execute code. While the exact nature of the payload is not clear from static analysis, the overall structure points towards a delivery mechanism for malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 8

  • Adobe Reader LibTIFF XFA image exploit — CVE-2010-0188 critical CVE likely CVE_2010_0188
    PDF contains the CVE-2010-0188 exploit template: XFA JavaScript heap-spray setup, a generated TIFF image payload, and assignment of that TIFF data to an XFA image field rawValue to trigger Adobe Reader's LibTIFF parser.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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 script payload in PDF stream info 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.
  • 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/ In PDF document text
    • http://ns.adobe.com/xdp/In PDF document text
    • http://www.xfa.org/schema/xci/1.0/In PDF document text
    • http://www.xfa.org/schema/xfa-data/1.0/In PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin pdf-embedded-file PDF EmbeddedFile object 41 at offset 0xB02 85 bytes
SHA-256: c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
embedded_file_obj0042.bin pdf-embedded-file PDF EmbeddedFile object 42 at offset 0xBB4 1029 bytes
SHA-256: dda0835df994b8be920f715db36452f6cee7bb42bbc9c897f878a7b298ba8e91
embedded_file_obj0121.bin pdf-embedded-file PDF EmbeddedFile object 121 at offset 0xDCE 65084 bytes
SHA-256: e0a11f2bbb2080e1b6a4585acb02687531d9934ae384c3bd2467b4780022cf55
Detection
ClamAV: No threats found
Obfuscation or payload: likely
262 of 337 identifiers look randomly generated (e.g. 'yVsbaZsecJgKELtcZImWJSFGgNfoHeKVrIQxSAlE'); 4 string-concatenation chain(s) — consistent with name-mangling obfuscation.
embedded_file_obj0044.bin pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x3276 144 bytes
SHA-256: 3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
embedded_file_obj0045.bin pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x3323 77 bytes
SHA-256: 10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275