Microsoft has removed 119 extensions from the Edge add-on store which were all tied to one adware campaign. In a paper titled “ Inside StegoAd: How We Disrupted a Massive Malicious Extension Campaign ,” Microsoft researchers detail how they uncovered and dismantled a sophisticated malware campaign that abused browser extensions to infect users. According to Microsoft, the campaign involved 119 malicious browser extensions which were downloaded by 2.6 million users. The extensions all promised, and delivered, some kind of basic functionality: ad blockers, VPNs, translators, video downloaders, calculators, coupon extensions and so on. But after a while they turned out to be “ sleepers ” and secretly started downloading additional malware. Among the payload was malware involved in ad fraud , but also extensions that ran arbitrary JavaScript pushed from the server, which stole Google credentials and second-factor codes at sign-in, harvested WordPress admin logins, and exfiltrated cookies in bulk for session hijacking. The name of the campaign “StegoAd” is derived from the words advertising and steganography , which means techniques of hiding secrets in something that doesn’t immediately cause suspicion. In this case, hiding code in images. And not only did the cybercriminals try to stay under the radar by waiting for some time, and hiding malicious code inside images, they also left some victims alone. Some of the extensions only went rogue in about 10% of installs, which would actually execute the next stage of the malware, while the other ~90% would be left alone (at least for that execution attempt). And, in some cases, they re-used names of well-known legitimate extensions to install an additional level of trust. Browser extensions are a source of wealth for cybercriminals because it compares to installing a small program that lives inside your browser, which can see and report about everything you do on the internet. Now I hear some of you thinking: I don’t use Edge. Or I’ve used it just once, to download and install my favorite browser. But although Microsoft discovered and analyzed the campaign, the techniques used in this campaign are applicable to Chromium-based browsers in general. This campaign was less about exploiting a browser vulnerability and more about tricking users into installing a trusted-looking extension, then using sophisticated concealment techniques to avoid detection long enough to compromise systems. How to stay safe Always be careful when downloading extensions, even from the reputable app stores. As we’ve seen many times before, criminals manage to get their apps or extensions listed when they are only one update away from turning into malware. So, make sure that you trust the developer and don’t rely on reviews alone. Use an up-to-date real-time security solution to detect and remove malicious extensions from your device and block connections to malicious domains and IP addresses. Remove the known malicious extensions from your browser. Below is an alphabetical list of the malicious extensions the researchers found by name. Please note that there might be more than one extension that has the same name. In case you doubt whether the extension you have installed is among them, check whether the ID matches the one shown in the list. If you prefer looking them up by ID, you can find them organized differently in the Microsoft report (pages 40-43). Extension Name Extension ID #Best# PDF Saver jebcdimkcimkafekgbgbhookdajcoeib “Download” Button for YouTube jbmkcmhocoddcokjkahpcchanlmiffhg “Save” Button for Pinterest fhkijdlfjnpimenfpnegkecbbijmoipm …Page Screenshot Clipper maiackahflfnegibhinjhpbgeoldeklb 7TV nmhdjlflloeeahacgomilnhmpfnhlpkn Adblock aooacabidfijofopjaeligonlfobjcjb Adblock dckihkcdmjmlkndgmmgplpcnkmdpangb Adblock (µBlock clone) kmiahfbflcnmlobepelpgkmolhodmiek Adblock For Edge kikacehfccglblphddbifmiaeiglfdfi Adblock Master dgmpkflgbcbpjgniahjegbpelmofbgnn Adblock Master hninibdhkeepfndhcdknlijeapngbgdp Adblock Master for Youtube jnakfjmfmjmfpmdnghedafdphdanbjkh Adblock for Youtube afakckepbbffmnoghgpfnnebijeahjcb Adblock for Youtube gclhifbbggfamoojmienffegbmmfnfll Adblock for Youtube nipggfgilmoiofmnkbeabghbcaohmjih Adblocker FX fkkoeecbjckjpnmenebojblcljjgbpoj Adblocker Plus for YouTube imiheoejheaebigkjaeilfmekiikjdbd AdFly Skipper for Edge nhfohdhgahjpmniccbgflilignkcnmai AdSkip-爱奇艺 mimmainmmkddahakleojidjaimaofndp Ads Block Ultimate fbobegkkdmmcnmoplkgdmfhdlkjfelnb AI Search GPT for Edge beemogkfhphmjghmkghdaggidgohohee AI Search with ChatGPT jgngkchljnldpnjimaboboomjmpfpoie AI Weather Forecast iaehhmhmdidpkfmddiodkloefndpggcj AliExpress Helper elecjoakfjcmjoppfconlfgfemjcaoea Auto Skip Ads on YouTube dcelinkcepeidliddjhapgjokheoldjb Axure RP Viewer aekfeebhjlmielppjlhebapokdkelion Batch Image Downloader hnleilhpfbdofpdnnpjggafhncienakg Batch Image Downloader ibfjnghdeenopfkpbmnkablkfejnlnif Best Speedtest Tool eklcgjodcnhhcghpbhehhbnmjncbopcg Best YouTube Adblocker cjjcndlebdepeddfopnhpifmbfecocfh Color Enhancer bmmchpeggdipgcobjbkcjiifgjdaodng Color by Number aljmdjbcbkanlhnmcdjbefaomgbekhno ColorZilla mdjeohcdegpfoppocljbccpognjlkjke Convert Everything ielbkcjohpgmjhoiadncabphkglejgih Cool Cursor ajbkmeegjnmaggkhmibgckapjkohajim CrxMouse – Super Drag pohfogacehhgefhgmcmnojflfakllkal CrxMouse Gestures imcbcfmohachfahkbgijokokjpfmoogb Custom New Tab for Edge dbhgpbaaedlknnnochmkjfacnfnakkfa Downloader for Instagram higdalghhdbfffdjdiaenminajlmmldb Download All Images hnggnhinapdcjocbciajaffnofecfale Edge Web Highlighter ijgobfhjjipoljjcejmafocdnfnloflm Efficient Adblocker for Youtube oejbpnadmkdiofacgknaaagbmmonhgpb Enhance YouTube jecnjeedhbokmpckobjbgieglfjcomek Evernote in Pinned Tab elljfaejhdaplocgcejlhfemgimbmcdp Focus To-Do: Pomodoro Timer & To Do List nlapjaaepfeadiecaipnacimidfjginj Free Online Video Downloader bpdanoaacmebjgfjdmekfcfgmnaoekim G.B.B.D Translator fdjpommjpahieenehallhicdhponhacm GIPHY for Edge gggjlnkbmgmjboipaegjmjmehmcekamo Gmail Checker nhjdhmbdahdidccpobobccagmmijndmp Google Hangouts adnahjjfjjemdiefpobclponnhkijnmo Google search link fix mjofmhcbolkekhebpccldlbdamnfjefc Google Translate in Right Click fcoongackakfdmiincikmjgkedcgjkdp Hiddence VPN akfklmfpgmkkhiiolnfbhalkeccjnmeb HLS Stream Downloader fgbfcndckldbjifhjgijpjmnpekkelkb IG Downloader for Edge ncbpkjcnklnbnkjpcamhhoedlkljeolo Image Downloader – Batch Download ngeoikidkjbegoifbnmfimacmbilfcgi Image Downloader Pro gnbnbmnldhfoplgjojhepikgjanaplle Imageye ikfdcmchafnmklcndfegdlefcfoaggni ImTranslator bbofakpgfmlfjpjcahodgpbddocpibge iQiyi Adblock hlkenllnegiplhjhpobgangolfkjcgab iVideo Downloader amfboegfahhedgehddflgcfbdaapllfj iYouTubeToMP4 bemebcpaekkmffjjbdakpipemmmlgchb Language Reactor hffpfdhdjpbnaddaidajedimmpckekkl Live Start Page egbkgelnkodaldbpkgjmhcekjakkcpnk Magic Actions for YouTube pjhoiegecdlpaohfffpajaldpbilngog Marinara: Pomodoro® Assistant mebgpfbaibhepnkljpimlijicgkbangk Mouse Tooltip Translator ibjjllhemkfgfbkgohldepcdgiigpdkb Natural Reader Text to Speech eopjamlpanhfkcbnoeofcnmdfdiogfgl New Tab – Customized Dashboard edohfgmjmdnibeihfcajfclmhapjkooa Night Mode engcfdjknekakgpjkhdobneidcpfbfgm Night Mode pgcamkdibinodcpkhenjmofbfobpebpn One Key Translate jihipmfmicjjpbpmoceapfjmigmemfam Picture-in-Picture Playing kemjiblbeciejjlgobbkffbpnceieefh Piggy – Automatic Coupons gmaoimcaoimgmomockloieoifjocpkmf Pinterest Save Button kakgeonhimhojdncehlopejkfaapboeo Return YouTube Dislike cgoigjefilgfmcjnnendlpdaonlfoncf RSS Feed gmciomcaholgmklbfangdjkneihfkddd Save as PDF mlgefgipndlgdfjfgnjfheigkagjieea Save Pinterest on Right Click glgbgppjjkldoifgpbhbpbkbcdjpgpfj Screen Shader | Dark Mode olcibgopfmndlnghnmogcgdhdffdbicg Similar Sites – Discover Related Websites fifeankddgioinbcchlokclbcgjlopjj Similar Sites for Edge fhhinoefbjlmhakpjohnpabdobgmphli Simple mass downloader dbhdfkiddhdhmcikjdgblfjbenjfjlfh Social Book Post Manager inelenlaldjofeekhjinpjkacjokagke SpeakIt! badiigfpcpfckbhmpmkhokagppaadkim Speed Control for Youtube eindenipbnkpeofhpjjimphfchmjoohe Spell & Grammar Check Tool fljmegmgjebjdionedkjfgffikhnmcgg ssYoutube – Video Downloader okmfpehbgckbneedidbladdaiekikcdo Summary with ChatGPT dokiamnhbobapjfhhhcjlfplabeofamp Super Dark Mode for Edge lkmeakjjodlkhbikbpdoeicfodaklkna TikMate jhahljcmjemimhchigiaigklabnpodgo TikTok APP for Edge celdediiemogjpfcjocdbildilkccepl TikTok Downloader Without Watermark flcgalphjnojjefjnnimnejbkkefbjgo To QRcode cgjomicbgmoadggnjbdiafpjlodmafkp Transkriptor lplondnihmdhjokafldkcfnjclkhigpm Translate Officer jjdfciihihcpgfgmoonfpgglbgclpfai Translate Selected Text with Google obocpangfamkffjllmcfnieeoacoheda Translate Selected Text with Right Click fmchencccolmmgjmaahfhpglemdcjfll Trusted VPN for Edge – Free VeePN klmfgbnlbfgpdenpdddpdfigmnkmchil Turbo Download Manager bpjnmlookdfciblphehedlcbpmignahe Twitch Custom Emotes – FrankerFaceZ johcbgkljdbebbloakcollpmigpigkpd U-Tube Downloader nphphgkcccnlmdiihcedabnhfacfmojk Undo Closed Tabs amemnenomfejhfmfiheekmbcigfkolel Unblock Youku ajnjfpjimckjhfcpkaldennpdjglmeml UseChatGPT.AI hcmfdagipflbaagmcnhnhabkmjkopcke Video & MP3 Downloader oiolhdeinoaidggfcpebifcbedppbgog Video Downloader Premium jgphopeamnghlcekffldkpnbhmiadnbc VPN pdnjhppcgkdbjolbeplcabkcfmpnbjmh Weather Forecast hecicojipmfmablnbhknedademofbbpk Webpage Screenshot for Edge eblienbdkbgiigaebhmljbedkafiobkj YouTube Transcript to Text nfincgjfplibcdcncfkeehldffppnlnp YouTube Adblock Plus flmkfmdmcaepdaoedepihfkhmgopiago Youtube Adblock Online hmjdegfgppjddmmojloflajkelegnjdp Youtube Download dhnibdhcanplpdkcljgmfhbipehkgdkk Youtube To MP4 Downloader cfilkckedhoniijcpjfgihelgepflpni ZLibrary Searcher ffedaeoanbhgmanhhecfjodpopcjnhkc 一键翻译 nepdfkaidpemglngbgpnmmhnleiekpin 鼠标手势 (Mouse Gestures) cbopgngpbfeoecnbebghbbhmdadmllce We don’t just report on threats—we remove them Cybersecurity risks should never spread beyond a headline. 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