Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb2336482d0e9bed…

MALICIOUS

PDF

6.2 KB First seen: 2026-05-11
MD5: 9bad511fa7967ca73c3cd4573797fd9d SHA-1: 5de800cdf4ee5f4b562c482839410978570db54a SHA-256: cb2336482d0e9bed6dab9bb1f30136305b47cc7be53b78c0f6fa6b66152a1d31
198 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, PDF_EVAL, and PDF_UNESCAPE. The JavaScript stream, identified as stream_002_off00000324.js, is heavily obfuscated using eval() and unescape() calls, suggesting it's designed to hide its malicious functionality. The primary intent appears to be the execution of arbitrary code, likely to download and run a secondary payload, which is a common technique for initial access or further system compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 5

  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
    /*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/eval(/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/unescape(/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/this.subject.replace(/Y/g,String.fromCharCode(37)).replace(/R/g,'F')/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/)/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/);
  • 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. (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://www.w3.org/1999/02/22-rdf-syntax-ns# In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
🗂 Part of campaign: 2iii.org 14 samples

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off00000324.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0x324 295 bytes
SHA-256: 0c76cda798ef77d3534d0ecfe9b37e2225dfe992b937194fe3020d8fc0ba3acc
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
objstm_0024_00.bin pdf-objstm-decoded PDF /ObjStm 24 0 obj (inflated) 331 bytes
SHA-256: 4b2e40328f06c5285b826a34449e48de07c567b35612d9183d9aa8832241bc95