[About XDA developers] tin2001:
Some bastard dodgy javascript is replacing the entire page, every page, with a bloody embedded image ad. It's just taken me about 5 attempts to log in and reload this page to post this.

At the top of the page body is a dodgy looking "eval" script. It decodes to an equally dodgy looking obfuscated js script:

!function t(e,n,r){function o(a,d){if(!n[a]){if(!e[a]){var c="function"==typeof require&&require;if(!d&&c)return c(a,!0);if(i)return i(a,!0);var s=new Error("Cannot find module '"+a+"'");throw s.code="MODULE_NOT_FOUND",s}var u=n[a]={exports:{}};e[a][0].call(u.exports,function(t){var n=e[a][1][t];return o(n||t)},u,u.exports,t,e,n,r)}return n[a].exports}for(var i="function"==typeof require&&require,a=0;a<r.length;a++)o(r[a]);return o}({1:[function(t,e,n){"use strict";!function(){function e(t,n,r,o,i,a,d,c,s,u,p,f){window.adonisWrapper=window.adonisWrapper||{},window.adonisWrapper.log=function(){!0===t&&console.log.apply(console,arguments)},delete document.write,window.adonisWrapper.log("withinIframe running at depth",f);var l=['<script type="text/javascript">(',e.toString(),")(",[t.toString(),n.toString(),r.toString(),o.toString(),i.toString(),a.toString(),d.toString(),c.toString(),s.toString(),u.toString(),"'"+p+"'",f+1].join(",").toString(),")<","/script>"].join(""),g=[],w=window.XMLHttpRequest.prototype.open;window.XMLHttpRequest.prototype.open=function(t,e){var n=[].slice.call(arguments);return this._url=e,g.push(this),w.apply(this,n)},n()(HTMLIFrameElement,"name",r(),o(l)),n()(HTMLIFrameElement,"contentDocument",d(a(l),i()),c()),n()(HTMLIFrameElement,"contentWindow",s(a(l),i()),u());var v=["script","img"];document.addEventListener("load",function(t){window.adonisWrapper.log("withinIframe load event",t.target),t.target&&-1!==v.indexOf(t.target.nodeName.toLowerCase())&&void 0===t.target._loadState&&(t.target._loadState="load")},!0),document.addEventListener("error",function(t){window.adonisWrapper.log("withinIframe error event",t.target),t.target&&-1!==v.indexOf(t.target.nodeName.toLowerCase())&&void 0===t.target._loadState&&(t.target._loadState="error")},!0),window.addEventListener("message",function(t){if(t.origin===p&&void 0!==t.data.iframeId){window.adonisWrapper.log("message received "+t.data.iframeId);var e=t.data,n=function e(n){var r={originIframeId:n.iframeId,readyState:document.readyState,requestData:[],cssData:[]};if(void 0===n.fetchSrcElementStatus||n.fetchSrcElementStatus)for(var o=document.querySelectorAll(v.join(",")),i=0;i<o.length;i++){var a=o[i];if(a.src&&void 0!==a._loadState)r.requestData.push({type:a.nodeName,src:a.src,state:a._loadState});else if(a.src)return window.adonisWrapper.log("Wait for event from "+a.src),a.addEventListener("load",function(){e(n)}),void a.addEventListener("error",function(){e(n)})}if(void 0===n.fetchXHRStatus||n.fetchXHRStatus)for(i=0;i<g.length;i++){var d=g[i];if(4!==d.readyState)return window.adonisWrapper.log("Wait for event from "+d._url),d.addEventListener("load",function(){e(n)}),void d.addEventListener("error",function(){e(n)});r.requestData.push({type:"XHR",src:d._url,state:0===d.status?"error":"load"})}var c=n.displayTypes,s=n.cssAttributes;void 0!==c&&void 0!==s&&(o=document.querySelectorAll(c.join(",")),Array.prototype.forEach.call(o,function(t){var e=window.getComputedStyle(t),n={};s.forEach(function(t){n[t]=e.getPropertyValue(t)}),r.cssData.push({type:t.nodeName,id:t.id,class:t.getAttribute("class"),cssAttributes:n})})),window.adonisWrapper.log("send response "+n.iframeId),t.source.postMessage(r,p)};!function(t){"loading"!==document.readyState?t():document.addEventListener("DOMContentLoaded",t)}(function(){n(e)})}})}t(2).version;window.adonisHash=window.adonisHash||window.location.hash||"",window.adonisWrapper=window.adonisWrapper||{};var n=-1!==window.adonisHash.indexOf("adonis-logging");if(window.adonisWrapper.log=function(){n&&console.log.apply(console,arguments)},navigator.userAgent.indexOf("Edge")>=0||navigator.userAgent.indexOf("Trident")>=0)return void console.warn("FIXME: EdgeSupport.");var r=function(){return function(t,e,n,r){var o=Object.getOwnPropertyDescriptor(t.prototype,e);Object.defineProperty(t.prototype,e,{get:function(){return n(o.get,this,arguments)},set:function(){return r(o.set,this,arguments)},enumerable:!0})}},o=function(){return function(t,e,n){return t.apply(e,n)}},i=function(t){return function(e,n,r){try{var o=r[0];if(-1!==o.indexOf("html")){var i=o.split(";"),a=i[1],d=parseInt(a)+t.length;i[1]=d.toString(),o=i.join(";"),o=o.replace("<head>","<head>"+t),r[0]=o}}catch(t){window.adonisWrapper.log(t)}return e.apply(n,r)}},a=function(){return function(t){var e=!1;if(t.src&&0!==t.src.indexOf("javascript:")&&0!==t.src.indexOf("about:blank")){var n=document.createElement("a");n.href=t.src;n.host===window.location.host&&(e=!0)}else e=!0;return e}},d=function(t){return function(e,n){var r=n.write;n.write=function(e){try{if(!this._injected){var n=/<(?!(body|head|html|doctype))([^>!\/\s]+)/i;n.test(e)&&(e=e.replace(n,function(e){return t+e})),this._injected=!0}}catch(t){window.adonisWrapper.log(t)}return r.call(this,e)}}},c=function(t,e){return function(n,r,o){var i=n.apply(r,o);try{if(r.contentDocumentDecorated)return i;e(r)&&(r.contentDocumentDecorated=!0,t(r,i))}catch(t){window.adonisWrapper.log(t)}return i}},s=function(){return function(t,e,n){return t.apply(e,n)}},u=function(t,e){return function(n,r,o){var i=n.apply(r,o);try{if(r.contentWindowDecorated)return i;if(e(r))try{r.contentWindowDecorated=!0,t(r,i.document)}catch(t){window.adonisWrapper.log("The following frame was supposed to be friendly but we got a security violation while attempting to decorate:",r)}else window.adonisWrapper.log("This frame is not friendly",r)}catch(t){window.adonisWrapper.log(t)}return i}},p=function(){return function(t,e,n){return t.apply(e,n)}},f=['<script type="text/javascript">(',e.toString(),")(",[n.toString(),r.toString(),o.toString(),i.toString(),a.toString(),d.toString(),c.toString(),s.toString(),u.toString(),p.toString(),"'"+window.location.origin+"'",0].join(",").toString(),")<","/script>"].join("");r()(HTMLIFrameElement,"name",o(),i(f)),r()(HTMLIFrameElement,"contentDocument",c(d(f),a()),s()),r()(HTMLIFrameElement,"contentWindow",u(d(f),a()),p())}()},{2:2}],2:[function(t,e,n){"use strict";e.exports={version:"7.10.5"}},{}]},{},[1]);

What I'm seeing is the actual page I wanted for a second or 2, and then the entire page disappears (literally - the scroll length goes from several "pages" to just over 1), and I get a banner ad (as base64 embedded, not linked to) on a grey background. Possibly it's a bad anti-adblock script - I am running adblock plus.