Malicious PDF — malware analysis report

Static analysis result for SHA-256 83bd6b6affa1a026…

MALICIOUS

PDF

120.9 KB
MD5: 5bdf917bb828f91c734b9ea8441d506a SHA-1: 371dede5dd7b91ebfbadbe4d3d831575f2f3bdf9 SHA-256: 83bd6b6affa1a026af1805d62123579e952d93e0afdf338309f0d9557c80049c
262 Risk Score

Malware Insights

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

The PDF file contains XFA (XML Forms Architecture) content which is known to be a vector for exploits. Heuristics indicate exploitation of CVE-2010-0188, a vulnerability in Adobe Reader's LibTIFF component, to execute a JavaScript stager. This stager, identified as 'xfa_numeric_stage_000.js', appears to download a second-stage payload from the reconstructed URL 'http://tsikarnore.myvnc.com/w.php?f=4c20600f&fe=400000'.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • 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: Pdf.Exploit.Dropped-78 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Dropped-78
  • 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
  • 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
a3046cb43a287a387c5756cd60f59f4ca748dccd8ba8743f5b1f173d372bf5af
deobfuscated-js XFA split character-table decoded JavaScript (raw) at offset 0x2E1 3786 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).