Malicious PDF — malware analysis report

Static analysis result for SHA-256 744be7443e887631…

MALICIOUS

PDF

52.3 KB
MD5: d53e3ff826d9a9e120970dee952f7fb5 SHA-1: ff9c855827e8281fe8f3e5df722c9eec59024ba8 SHA-256: 744be7443e887631726879272ed3693db7c52dae33ef9245369f2a1040b5ddc1
262 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's LibTIFF component, to achieve code execution. A JavaScript stager was recovered from the XFA form, which contains obfuscated code. This script is responsible for downloading and executing a second-stage payload from the reconstructed URL 'http://158.255.211.92:8080/w.php?f=4&e=4'. The ClamAV detection 'Js.Exploit.HTML-30' further supports the malicious nature of the embedded JavaScript.

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: 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
  • 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
7673519016de10475bb8c1383dc7f77cf81e8d0df0392ae90f1efa6530908ec0
deobfuscated-js XFA replacement character-table decoded JavaScript (raw) at offset 0x30C 3763 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).