Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fb8757c00365ffc…

MALICIOUS

PDF

24.2 KB
MD5: 681b35a470f12076965a8815b93b4913 SHA-1: e98694bd2e6b6fe3a66de62efe679c90aa7a9d08 SHA-256: 3fb8757c00365ffc7719184e8d6230091869dca6eb50c72b56532ab49940b056
268 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.001 Malicious Link: Malicious Link T1059 Command and Scripting Interpreter T1059.001 Command and Scripting Interpreter: PowerShell T1059.007 Command and Scripting Interpreter: JavaScript/JScript

The PDF file contains XFA form elements that trigger a known vulnerability (CVE-2010-0188) in Adobe Reader. This vulnerability is used to execute a stager script, which in turn is detected by ClamAV as Js.Exploit.HTML-30. The extracted JavaScript is responsible for downloading and executing a second-stage payload. The embedded URL is likely part of this delivery mechanism.

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: 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.
  • Suspicious extracted artifact high 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.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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
088297143b7b97d25ad41e0c0f956e5a1de2c06488467854c6a626ba1b3af696
deobfuscated-js XFA rawValue numeric decoded JavaScript (raw) at offset 0x3A8 3739 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).