Malicious PDF — malware analysis report

Static analysis result for SHA-256 1461b8ede0b66b47…

MALICIOUS

PDF

51.4 KB
MD5: 137dae31da14732e8b4aba5b5bced8a8 SHA-1: 3fc824d1e6ab6cfb99729b88d594c0d25bdc9f75 SHA-256: 1461b8ede0b66b47af863e407d71068ff6f306490942656a29213e1ddbf4ed6a
264 Risk Score

Malware Insights

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

The PDF file exploits CVE-2010-0188, a vulnerability in Adobe Reader related to XFA forms and LibTIFF. A JavaScript stager was recovered and deobfuscated, which contains a URL pointing to 'http://muntty.tw/w.php?f=26&e=34'. This script is designed to download and execute a second-stage payload, indicated by the ClamAV detection of 'Js.Exploit.HTML-30' and 'Pdf.Exploit.Agent-36962'.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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.
  • 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PSEOF. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xfa_numeric_stage_000.js
2c7ad2183fb72d747729bf465a7a4c151839cf7690be3a18e6f140e6a0822724
deobfuscated-js XFA replacement character-table decoded JavaScript (raw) at offset 0x30C 3723 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).