Open4u Open4u is a browser hijacking app, created to display sponsored advertisements and redirect prompts on every web page the users visit through their browser. Open4u can also promote different search engines, homepages, toolbars, and other browser components by replacing the existing ones with them. Open4u is a new representative of the browser hijacker category that usually displays multiple advertisements (such as pop-up messages, banners, text links, new tabs, box notifications, etc.) directly on the web browser\u2019s screen during the browsing sessions. To ensure better control over the content that gets shown on the screen, the hijacker can typically install a search engine of its own and replace the homepage with one that automatically redirects to specific sponsored pages.\u00a0No web browser is immune against being hijacked by an application like Open4u, therefore even web users who use well-known and safe browsers such as Chrome, Firefox, Edge, and Safari can experience the annoyance of the numerous advertisements on their screen and the imposed browser modifications. This article, however, has been created in response to the growing number of web users who have been asking us how to deal with the different advertisements and the potentially unwanted browser changes that have been disturbing their web browsing activity. That\u2019s why below we have published a removal guide with instructions that explain exactly how to remove Open4u and uninstall its changes. Open4u virus on phone A browser hijacker such as Open4u can become part of your system in many different ways. Sometimes, you may let it get installed when you visit a web page that prompts you to download some free applications. In other cases, you may get it installed when you download torrents from free file-sharing sites, or when you click on some spam message in your inbox and download its free attachment. Among the diverse ways of browser hijacker distribution, however, the most commonly employed one is to bundle it into the software package of another free and attractive program, game, software optimizer, free audio or video player, etc. \u00a0Therefore, you should always read the EULA and check thoroughly the installers of any new programs in your system and especially the Advanced\/Custom settings where programs like Open4u can often be found. Can Open4u put your system in danger? Browser Hijackers are generally harmless programs used for aggressive online advertising. Yet, the ads, banners, pop-ups and redirect links they display typically manage to irritate the end-users to such an extent that they consider such programs for some sort of redirect viruses and even put their name next to malware such as Ransomware and Trojans. However, in reality, programs like Open4u are not able to carry out the deceptive activities that a real Ransomware or a Trojan horse can perform. Still, even though it is far from a virus, you might prefer to uninstall the browser hijacker and remove its ads due to a number of other reasons. For instance, such software can often interrupt your browsing sessions with irrelevant and annoying offers, promotions, coupons, notifications for different deals and similar commercial messages. And even if you try to put that disturbance aside, it will be hard to ignore the browser\u2019s unresponsiveness and the sudden crashes that may take place every now and then due to system overloading with continuous page-redirecting and ad-generating processes. \u0002 SUMMARY: Name Open4u Type Browser Hijacker Danger Level Medium\u00a0(nowhere near threats like Ransomware, but still a security risk) Symptoms A Browser Hijacker will typically start to redirect your web searches to pre-defined URLs and to fill your screen with sponsored ads. Distribution Method Free software bundles may often contain Browser Hijackers inside their installation packages. Detection Tool Open4u Virus Removal If you have a Windows virus, continue with the guide below. If you have a Mac virus, please use our How to remove Ads on Mac guide. If you have an Android virus, please use our Android Malware Removal guide. If you have an iPhone virus, please use our iPhone Virus Removal guide Some of the steps will likely require you to exit the page. Bookmark it for later reference. Reboot in\u00a0Safe Mode\u00a0(use this guide if you don't know how to do it). WARNING! READ CAREFULLY BEFORE PROCEEDING! \u00a0 Press CTRL + SHIFT + ESC at the same time\u00a0and\u00a0go to the\u00a0Processes Tab (the "Details" Tab on Win 8 and 10). Try to determine which processes are dangerous.\u00a0 Right click on each of them\u00a0and select Open File Location. Then scan the files with our free online virus scanner: After you open their folder,\u00a0end the processes\u00a0that are infected, then delete their folders.\u00a0 Note:\u00a0If you are sure something is part of the infection - delete it, even if the scanner doesn't flag it. No anti-virus program can detect all infections.\u00a0 Hold together the Start Key and R. Type\u00a0appwiz.cpl -->\u00a0OK. You are now in the Control Panel. Look for suspicious entries.\u00a0Uninstall it\/them. Type msconfig in the search field and hit enter.\u00a0A\u00a0window will pop-up: Startup --->\u00a0Uncheck\u00a0entries that have "Unknown" as Manufacturer or otherwise look suspicious. \u00a0 Hold the Start\u00a0Key\u00a0and\u00a0R\u00a0- \u00a0copy +\u00a0paste the following and click OK: notepad %windir%\/system32\/Drivers\/etc\/hosts A new\u00a0file will open. If you are hacked, there will be a bunch of other IPs connected to you at the bottom. Look at the image below: If there are suspicious IPs below "Localhost" -\u00a0write to us in the comments. Open the start menu and search for Network Connections (On Windows 10 you just write it after clicking the Windows button), press enter. \tRight-click on the Network Adapter you are using --->\u00a0Properties --->\u00a0Internet Protocol Version 4 (ICP\/IP), click \u00a0Properties. \tThe\u00a0DNS line should be set to Obtain DNS server automatically. If it is not, set it yourself. \tClick on Advanced --->\u00a0the DNS tab. Remove everything here (if there is something)\u00a0--->\u00a0OK. \tAfter you complete this step, the threat will be gone from your browsers. Finish the next step as well or it may reappear on a\u00a0system reboot. Right click\u00a0on the browser\u2019s shortcut --->\u00a0Properties. NOTE: We are showing Google Chrome, but\u00a0you can do this for Firefox and IE (or Edge). Properties \u2014\u2013> Shortcut.\u00a0In\u00a0Target, remove everything\u00a0after\u00a0.exe. \u00a0\u00a0Remove Open4u\u00a0from Internet Explorer: Open\u00a0IE, click\u00a0\u00a0\u00a0\u2014\u2013>\u00a0Manage Add-ons. Find the threat\u00a0--->\u00a0Disable. Go to\u00a0\u00a0\u2014\u2013>\u00a0Internet Options --->\u00a0change\u00a0the\u00a0URL\u00a0to whatever you use (if hijacked) --->\u00a0Apply. \u00a0Remove\u00a0Open4u\u00a0from Firefox: Open\u00a0Firefox,\u00a0click\u00a0\u00a0\u00a0 \u2014\u2014->\u00a0Add-ons\u00a0---->\u00a0Extensions. Find the adware\/malware\u00a0--->\u00a0Remove. Remove\u00a0Open4u\u00a0from Chrome: Close Chrome. Navigate to: \u00a0C:\/Users\/!!!!USER NAME!!!!\/AppData\/Local\/Google\/Chrome\/User Data.\u00a0There is\u00a0a Folder called "Default" inside: Rename it to Backup Default. Restart Chrome. Type Regedit in the windows search field and press Enter. Inside, press CTRL and F together and type the threat's Name. Right click and delete any entries you find with a similar name. If they don't show up this way, go manually to these directories and delete\/uninstall them: \tHKEY_CURRENT_USER----Software-----Random Directory. It could be any one of them - ask us if you can't discern which ones are malicious. HKEY_CURRENT_USER----Software---Microsoft----Windows---CurrentVersion---Run-- Random HKEY_CURRENT_USER----Software---Microsoft---Internet Explorer----Main---- Random If the guide doesn't help, download the\u00a0anti-virus program we recommended or try our free online virus scanner. Also, you can always ask us in the comments for help!