Malicious PDF — malware analysis report

Static analysis result for SHA-256 87e639c4ce841972…

MALICIOUS

PDF

31.7 KB
MD5: 111370bf536cba68e989e5ef4fa5d0cf SHA-1: 0768ace6b4a71e49df4ba9c40927783fcf712664 SHA-256: 87e639c4ce841972cf852b6f5de165fe47159ef06b9e610682c1cc2bb8e44a39
342 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample is a PDF file that exploits CVE-2010-0188, a vulnerability in Adobe Reader related to XFA forms. The embedded JavaScript stager, identified as 'xfa_numeric_stage_000.js', contains logic to download a second-stage payload from the URL http://129.121.88.135/data/Home/w.php?f=&e=4. This indicates a clear intent to execute arbitrary code by leveraging a known exploit.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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.
  • 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: Js.Exploit.HTML-30 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Js.Exploit.HTML-30
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • XFA numeric JavaScript stager high PDF_XFA_NUMERIC_JS_STAGER
    PDF XFA script reconstructs a hidden JavaScript stage from numeric field data or a character table, then evals the result. The decoder is gated on XFA script, numeric staging, and recovered exploit-like JavaScript or shellcode markers.
  • PDF exploit shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF exploit shellcode contains a hardcoded http(s) URL — stored as little-endian %uXXXX Unicode escapes, or hex-encoded in a document metadata field (/CreationDate, /Title) and referenced from the decoded script. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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-template/2.5/
    • http://129.121.88.135/data/Home/w.php?f=&e=4

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xfa_numeric_stage_000.js
d273b78c558329219d34500b0339a87bfa2d15d76efd858a4357161c832d16c6
deobfuscated-js XFA rawValue numeric decoded JavaScript (raw) at offset 0x3D2 3783 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36962
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s). Carved artifact contains 3 long base64-like blob(s).