Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ae9c66afa3fcb4…

MALICIOUS

PDF

24.1 KB
MD5: 7dc0f927d1cff2033c6eea03eca09675 SHA-1: 1fb9cfc6a2dfe80643be4f2c5d072215df5038c3 SHA-256: 81ae9c66afa3fcb4e17cfa1aa154dca0959be74c19b5770ba9a4d4407b7ade56
230 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File T1059.001 Command and Scripting Interpreter: PowerShell T1059.003 Command and Scripting Interpreter: Windows Command Shell T1059.007 Command and Scripting Interpreter: JavaScript/TypeScript

The PDF file contains XFA form elements that trigger a critical vulnerability (CVE-2010-0188) in Adobe Reader. This vulnerability is used to execute a stager written in JavaScript, which is then deobfuscated. The deobfuscated JavaScript is detected by ClamAV as Js.Exploit.HTML-30 and is likely responsible for downloading and executing a second-stage payload. The embedded URL is likely related to the exploit or payload delivery.

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
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).