Malicious PDF — malware analysis report

Static analysis result for SHA-256 838c5bb4088fe9b0…

MALICIOUS

PDF

121.9 KB
MD5: d67c5b83ccd8046ed5c425e71451bd67 SHA-1: 3287225ac196a377704764cc4f5dcd7ece32981c SHA-256: 838c5bb4088fe9b0217a0f42cdec193d90487e549ca5ab74481189604e2c101a
262 Risk Score

Malware Insights

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

This PDF exploits CVE-2010-0188, a vulnerability in Adobe Reader's handling of XFA forms, to execute a JavaScript stager. The deobfuscated JavaScript contains a URL that is likely used to download and execute a second-stage payload. The embedded URL 'http://unfai.blueewaterled.biz/w.php?f=5e91c6&e=4' is highly suspicious and is the primary indicator of compromise.

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
8b908c3d77c29ed3d09b1001aec8cf9da0f080fcbce5459eb70d0b02f8287663
deobfuscated-js XFA split character-table decoded JavaScript (raw) at offset 0x2E1 3798 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).