{"id":487405,"date":"2023-04-12T15:48:44","date_gmt":"2023-04-12T13:48:44","guid":{"rendered":"https:\/\/mybroadband.co.za\/news\/?p=487405"},"modified":"2023-04-12T15:59:38","modified_gmt":"2023-04-12T13:59:38","slug":"microsoft-fixes-5-year-old-bug-that-caused-firefox-to-munch-cpus","status":"publish","type":"post","link":"https:\/\/mybroadband.co.za\/news\/software\/487405-microsoft-fixes-5-year-old-bug-that-caused-firefox-to-munch-cpus.html","title":{"rendered":"Microsoft fixes 5-year-old bug that caused Firefox to munch CPUs"},"content":{"rendered":"

Microsoft has fixed a five-year-old bug in Windows Defender that caused significant CPU usage spikes for users of the Mozilla Firefox browser, Neowin reports<\/strong><\/a>.<\/p>\n

Firefox developer Yannis Juglaret confirmed that Microsoft rolled out a regular definition update for the anti-virus application that fixed the problem.<\/p>\n

The culprit in the CPU spikes was Windows Defender’s Antimalware Service Executable service, which appears as MsMpEng.exe<\/em> in the Task Manager.<\/p>\n

The service is necessary for Windows Defender to run its Real-Time Protection feature, enabled by default, that protects users from installing malware on their system.<\/p>\n

For several years, real-time protection consumed significantly more CPU resources with Firefox than Microsoft’s Edge browser or Google Chrome.<\/p>\n

The graph below from Neowin compares how much CPU consumption occurred when opening YouTube six times on the three browsers when the bug was first reported.<\/p>\n

\"\"<\/a>

CPU usage of Firefox, Edge, and Chrome compared at the discovery of the bug. Credit: Neowin<\/p><\/div>\n

The bug was fixed a few weeks ago thanks to a collaboration between Microsoft and the Mozilla development team.<\/p>\n

Juglaret said Mozilla expected the fix would mean the MsMpEng.exe<\/em> service should consume around 75% less CPU power while monitoring Firefox than it did before.<\/p>\n

Users running Windows versions as old as Windows 7 and Windows 8.1 have also received the update, despite the issue not impacting them.<\/p>\n

Juglaret added that only users who explicitly rejected definition updates would not get the fix.<\/p>\n

It is unlikely that many would have done this, as definition updates are critical to ensure that an anti-virus program can detect and neutralise the latest threats.<\/p>\n

\n

Now read: Microsoft previews tab sharing in Edge with Workspaces<\/a><\/h3>\n","protected":false},"excerpt":{"rendered":"

The culprit in the CPU spikes was Windows Defender’s Antimalware Service Executable service, which supports real-time malware protection.<\/p>\n","protected":false},"author":341042,"featured_media":487411,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_sma_x_autopost_status":"idle","_sma_x_autopost_error":"","_sma_x_post_id":"","_sma_facebook_post_id":"","_sma_instagram_post_id":"","_sma_threads_post_id":"","_sma_x_attempts":0,"footnotes":""},"categories":[16],"tags":[981,123,975,14109,43062,85537],"class_list":["post-487405","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-software","tag-firefox","tag-microsoft","tag-mozilla","tag-web-browsers","tag-windows-defender","tag-yannis-juglaret"],"_links":{"self":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/487405"}],"collection":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/users\/341042"}],"replies":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/comments?post=487405"}],"version-history":[{"count":1,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/487405\/revisions"}],"predecessor-version":[{"id":487473,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/posts\/487405\/revisions\/487473"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/media\/487411"}],"wp:attachment":[{"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/media?parent=487405"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/categories?post=487405"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mybroadband.co.za\/news\/wp-json\/wp\/v2\/tags?post=487405"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}