Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc6e1ba14a3bf8d9…

MALICIOUS

PDF

15.3 KB
MD5: 28592a3029f93cfb2bb95a02a687d35f SHA-1: c364db7f713135fc5f835dda3e4128b3ed9df8e8 SHA-256: fc6e1ba14a3bf8d9df264e3dad4a4424597ee49f35a260d3a45b04eb66dc8511
206 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1071.001 Web Protocols

The PDF sample contains embedded JavaScript that utilizes `eval()` and `unescape()` functions, indicating obfuscation and potential malicious code execution. The presence of XFA form elements and CCITTFaxDecode filter, along with ML classifier flagging, strongly suggests exploitation. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, as indicated by the heuristic firings and the nature of such PDF exploits. The URLs extracted are related to XFA, but their reputation is unknown, and they are not directly indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 10

  • CCITTFaxDecode + TIFF/XFA exploit prep — LibTIFF CVE-family indicator high CVE related PDF_CCITT_CVE_2010_0188_RELATED
    PDF uses /CCITTFaxDecode together with TIFF/XFA exploit-preparation markers such as rawValue image-field assignment, TIFF data, or heap-spray JavaScript. This matches the delivery pattern for Adobe Reader LibTIFF/CCITTFax parser exploit families, including CVE-2010-0188, but does not prove the exact malformed TIFF primitive.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/2.6/
    • http://www.xfa.org/schema/xfa-template/2.6/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0012_000.js
09de78b7de291aa3ddc78e96475725267630bf326894c1fb6b9aff709f8aec31
pdf-javascript-stream PDF /JS object 12 at offset 0x1BF2 363 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).