--- title: Malicious SIMs can shut down phones, steal files, and... description: Security researchers have discovered that standards-compliant SIM card functionality can be abused by malicious SIMs to shut down phones, steal files,... canonical: https://daily.dev/posts/malicious-sims-can-shut-down-phones-steal-files-and-drag-5g-back-to-2g-jsf41wtoy twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Malicious SIMs can shut down phones, steal files, and drag 5G back to 2G | daily.dev og:description: Security researchers have discovered that standards-compliant SIM card functionality can be abused by malicious SIMs to shut down phones, steal files,... og:url: https://daily.dev/posts/malicious-sims-can-shut-down-phones-steal-files-and-drag-5g-back-to-2g-jsf41wtoy og:image: https://api.daily.dev/og/posts/JSF41WToy.png og:image:alt: Malicious SIMs can shut down phones, steal files, and drag 5G back to 2G og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Malicious SIMs can shut down phones, steal files, and drag 5G back to 2G **[The Register](https://daily.dev/sources/theregister)** · 3 min read · 0 upvotes · 0 comments ## Summary Security researchers have discovered that standards-compliant SIM card functionality can be abused by malicious SIMs to shut down phones, steal files, downgrade 5G connections to 2G, hijack modems, and even execute code on devices. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Can a malicious SIM card downgrade a 5G connection to 2G? Yes. Researchers found that standards-compliant SIM card functionality can be abused to force a 5G connection to fall back to 2G, in addition to shutting down phones, stealing files, hijacking modems, and executing code — all using features that comply with existing telecom standards rather than exploiting implementation bugs. _Mobile and telecom security developments like this are tracked on daily.dev for engineers working on network-layer defenses._ ## Similar posts on daily.dev - [International Sting Takes Down SIM Box Criminal Network](https://daily.dev/posts/international-sting-takes-down-sim-box-criminal-network-udg2dfxkh) · Dark Reading · 0 upvotes · 0 comments - [India Orders Messaging Apps to Work Only With Active SIM Cards to Prevent Fraud and Misuse](https://daily.dev/posts/india-orders-messaging-apps-to-work-only-with-active-sim-cards-to-prevent-fraud-and-misuse-sd2ghsqsl) · The Hacker News · 0 upvotes · 0 comments - [India Introduces New Reforms To The Telecommunications Act](https://daily.dev/posts/india-introduces-new-reforms-to-the-telecommunications-act-gsuvmm3th) · Cyble · 0 upvotes · 0 comments - [Surveillance vendors caught abusing access to telcos to track people’s phone locations, researchers say](https://daily.dev/posts/surveillance-vendors-caught-abusing-access-to-telcos-to-track-people-s-phone-locations-researchers--2puwjln6z) · TechCrunch · 0 upvotes · 0 comments --- Tags: [#tech-news](https://daily.dev/tags/tech-news), [#security](https://daily.dev/tags/security) [View this post on daily.dev](https://daily.dev/posts/malicious-sims-can-shut-down-phones-steal-files-and-drag-5g-back-to-2g-jsf41wtoy) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Malicious SIMs can shut down phones, steal files, and drag 5G back to 2G","url":"https://daily.dev/posts/malicious-sims-can-shut-down-phones-steal-files-and-drag-5g-back-to-2g-jsf41wtoy","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/malicious-sims-can-shut-down-phones-steal-files-and-drag-5g-back-to-2g-jsf41wtoy"},"datePublished":"2026-08-11T09:41:41.983Z","dateModified":"2026-08-11T09:44:55.612Z","description":"Security researchers have discovered that standards-compliant SIM card functionality can be abused by malicious SIMs to shut down phones, steal files,...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/3bed03af9f990e17b544f570dd1dc29d?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/3bed03af9f990e17b544f570dd1dc29d?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"The Register","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"The Register","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/66aa2113fdad463992ffcbf0e8963fda","url":"https://daily.dev/sources/theregister"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/malicious-sims-can-shut-down-phones-steal-files-and-drag-5g-back-to-2g-jsf41wtoy","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"tech-news,security","timeRequired":"PT3M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"The Register","item":"https://daily.dev/sources/theregister"},{"@type":"ListItem","position":3,"name":"Malicious SIMs can shut down phones, steal files, and drag 5G back to 2G"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/malicious-sims-can-shut-down-phones-steal-files-and-drag-5g-back-to-2g-jsf41wtoy#faq","mainEntity":[{"@type":"Question","name":"Can a malicious SIM card downgrade a 5G connection to 2G?","acceptedAnswer":{"@type":"Answer","text":"Yes. Researchers found that standards-compliant SIM card functionality can be abused to force a 5G connection to fall back to 2G, in addition to shutting down phones, stealing files, hijacking modems, and executing code — all using features that comply with existing telecom standards rather than exploiting implementation bugs. Mobile and telecom security developments like this are tracked on daily.dev for engineers working on network-layer defenses."}}]} ```