{"id":39223,"date":"2025-06-10T12:32:36","date_gmt":"2025-06-10T12:32:36","guid":{"rendered":"https:\/\/ramsdata.com.pl\/url-files-as-an-attack-vector-how-opswat-reveals-hidden-threats\/"},"modified":"2025-06-10T12:32:36","modified_gmt":"2025-06-10T12:32:36","slug":"url-files-as-an-attack-vector-how-opswat-reveals-hidden-threats","status":"publish","type":"post","link":"https:\/\/ramsdata.com.pl\/en\/url-files-as-an-attack-vector-how-opswat-reveals-hidden-threats\/","title":{"rendered":"URL files as an attack vector: how OPSWAT reveals hidden threats"},"content":{"rendered":"<div class=\"relative flex-col gap-1 md:gap-3\">\n<div class=\"flex max-w-full flex-col grow\">\n<div class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal [.text-message+&amp;]:mt-5\" dir=\"auto\" data-message-author-role=\"assistant\" data-message-id=\"4ea1d10c-bbb9-4462-87c7-671f066e4fda\" data-message-model-slug=\"gpt-4o\">\n<div class=\"flex w-full flex-col gap-1 empty:hidden first:pt-[3px]\">\n<div class=\"markdown prose dark:prose-invert w-full break-words light\">\n<p data-start=\"343\" data-end=\"902\">Internet shortcut files, or so-called URL files, have for years been regarded as harmless and unimportant parts of Windows. However, they are now becoming increasingly used by cybercriminals and APT groups as part of complex infection chains. Thanks to the simplicity of the format, low detection rate and specific system behavior, URL files are becoming silent carriers of malicious code. Experts from <strong data-start=\"762\" data-end=\"807\"><a class=\"\" href=\"https:\/\/ramsdata.com.pl\/opswat\/\" target=\"_new\" rel=\"noopener\" data-start=\"764\" data-end=\"805\">OPSWAT<\/a><\/strong> are analyzing this new category of threats and providing tools to detect and neutralize them.    <\/p>\n<h2 data-start=\"904\" data-end=\"928\">Key findings<\/h2>\n<ul data-start=\"930\" data-end=\"1456\">\n<li data-start=\"930\" data-end=\"1013\">\n<p data-start=\"932\" data-end=\"1013\">URL files are text-based network shortcuts that can initiate multi-stage attacks.<\/p>\n<\/li>\n<li data-start=\"1014\" data-end=\"1120\">\n<p data-start=\"1016\" data-end=\"1120\">They are used to run .hta, .js or .cpl payloads, bypass security and leak data.<\/p>\n<\/li>\n<li data-start=\"1121\" data-end=\"1209\">\n<p data-start=\"1123\" data-end=\"1209\">These files can act as a phishing attack vector or as part of malware persistence.<\/p>\n<\/li>\n<li data-start=\"1210\" data-end=\"1317\">\n<p data-start=\"1212\" data-end=\"1317\">Even advanced APT groups use URL files as low-signal elements in larger campaigns.<\/p>\n<\/li>\n<li data-start=\"1318\" data-end=\"1456\">\n<p data-start=\"1320\" data-end=\"1456\"><strong data-start=\"1320\" data-end=\"1365\"><a class=\"\" href=\"https:\/\/ramsdata.com.pl\/opswat\/\" target=\"_new\" rel=\"noopener\" data-start=\"1322\" data-end=\"1363\">OPSWAT<\/a><\/strong> analyzes their structure statically and dynamically using FileTAC and MetaDefender Sandbox.<\/p>\n<\/li>\n<\/ul>\n<h2 data-start=\"1458\" data-end=\"1472\">Table of contents<\/h2>\n<ol data-start=\"1474\" data-end=\"1708\">\n<li data-start=\"1474\" data-end=\"1496\">\n<p data-start=\"1477\" data-end=\"1496\">What are URL files<\/p>\n<\/li>\n<li data-start=\"1497\" data-end=\"1536\">\n<p data-start=\"1500\" data-end=\"1536\">How URL files support cyber attacks<\/p>\n<\/li>\n<li data-start=\"1537\" data-end=\"1581\">\n<p data-start=\"1540\" data-end=\"1581\">Why the threat from them is growing<\/p>\n<\/li>\n<li data-start=\"1582\" data-end=\"1640\">\n<p data-start=\"1585\" data-end=\"1640\">Strategic use of URL files by APT groups<\/p>\n<\/li>\n<li data-start=\"1641\" data-end=\"1692\">\n<p data-start=\"1644\" data-end=\"1692\">How OPSWAT identifies malicious shortcut files<\/p>\n<\/li>\n<li data-start=\"1693\" data-end=\"1708\">\n<p data-start=\"1696\" data-end=\"1708\">Summary<\/p>\n<\/li>\n<\/ol>\n<h2 data-start=\"1710\" data-end=\"1730\">What are URL files<\/h2>\n<p data-start=\"1732\" data-end=\"1856\">A file with the extension .url is a simple INI-formatted Internet shortcut. Its structure is often limited to a single line:<\/p>\n<div class=\"contain-inline-size rounded-2xl relative bg-token-sidebar-surface-primary\">\n<div class=\"flex items-center text-token-text-secondary px-4 py-2 text-xs font-sans justify-between h-9 bg-token-sidebar-surface-primary select-none rounded-t-2xl\">ini<\/div>\n<div class=\"sticky top-9\">\n<div class=\"absolute end-0 bottom-0 flex h-9 items-center pe-2\">\n<div class=\"bg-token-bg-elevated-secondary text-token-text-secondary flex items-center gap-4 rounded-sm px-2 font-sans text-xs\"><button class=\"flex gap-1 items-center select-none py-1\" aria-label=\"Kopiuj\">Copy<\/button><span class=\"\" data-state=\"closed\"><button class=\"flex items-center gap-1 py-1 select-none\">Edit<\/button><\/span><\/div>\n<\/div>\n<\/div>\n<div class=\"overflow-y-auto p-4\" dir=\"ltr\"><code class=\"whitespace-pre!\"><span class=\"hljs-section\">[InternetShortcut]<\/span><br \/>\n<span class=\"hljs-attr\">URL<\/span>=https:\/\/OPSWAT.com\/<br \/>\n<\/code><\/div>\n<\/div>\n<p data-start=\"1912\" data-end=\"2156\">These files allow users to quickly launch a designated website or web application. However, this simplicity is also a potential weakness: the file does not require a signature, it can be easily modified, and launching it activates an external resource. <\/p>\n<h2 data-start=\"2158\" data-end=\"2195\">How URL files support cyber attacks<\/h2>\n<p data-start=\"2197\" data-end=\"2253\">Today, URL files are increasingly used as:<\/p>\n<ul data-start=\"2255\" data-end=\"2673\">\n<li data-start=\"2255\" data-end=\"2358\">\n<p data-start=\"2257\" data-end=\"2358\"><strong data-start=\"2257\" data-end=\"2280\">Phishing vectors<\/strong> &#8211; a user clicks on a shortcut that opens a malicious site or downloads a payload<\/p>\n<\/li>\n<li data-start=\"2359\" data-end=\"2436\">\n<p data-start=\"2361\" data-end=\"2436\"><strong data-start=\"2361\" data-end=\"2391\">Next-stage loaders<\/strong> &#8211; e.g., to run .hta or .js remotely<\/p>\n<\/li>\n<li data-start=\"2437\" data-end=\"2524\">\n<p data-start=\"2439\" data-end=\"2524\"><strong data-start=\"2439\" data-end=\"2480\">Security circumvention tools<\/strong> &#8211; e.g., bypass SmartScreen and MOTW tag.<\/p>\n<\/li>\n<li data-start=\"2525\" data-end=\"2600\">\n<p data-start=\"2527\" data-end=\"2600\"><strong data-start=\"2527\" data-end=\"2556\">Data leakage mechanisms<\/strong> &#8211; e.g., via an icon from SMB or C&amp;C beaconing<\/p>\n<\/li>\n<li data-start=\"2601\" data-end=\"2673\">\n<p data-start=\"2603\" data-end=\"2673\"><strong data-start=\"2603\" data-end=\"2636\">Threat persistence elements<\/strong> &#8211; placed in autostart folders<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"2675\" data-end=\"2756\">Although seemingly harmless, URL files can be part of a fully developed attack.<\/p>\n<h2 data-start=\"2758\" data-end=\"2800\">Why the threat from them is growing<\/h2>\n<p data-start=\"2802\" data-end=\"2886\">From <strong data-start=\"2820\" data-end=\"2854\">a URL file cybersecurity<\/strong> perspective, the threat comes from the fact that:<\/p>\n<ul data-start=\"2888\" data-end=\"3159\">\n<li data-start=\"2888\" data-end=\"2954\">\n<p data-start=\"2890\" data-end=\"2954\">These files are commonly ignored by traditional AV systems<\/p>\n<\/li>\n<li data-start=\"2955\" data-end=\"3016\">\n<p data-start=\"2957\" data-end=\"3016\">They can be easily smuggled through emails, documents and archives<\/p>\n<\/li>\n<li data-start=\"3017\" data-end=\"3091\">\n<p data-start=\"3019\" data-end=\"3091\">Not subject to close scrutiny by users or administrators<\/p>\n<\/li>\n<li data-start=\"3092\" data-end=\"3159\">\n<p data-start=\"3094\" data-end=\"3159\">May be modified by malware on an already infected system<\/p>\n<\/li>\n<\/ul>\n<h2 data-start=\"3161\" data-end=\"3217\">Strategic use of URL files by APT groups<\/h2>\n<p data-start=\"3219\" data-end=\"3505\">As the analysts point out <strong data-start=\"3242\" data-end=\"3287\"><a class=\"\" href=\"https:\/\/ramsdata.com.pl\/opswat\/\" target=\"_new\" rel=\"noopener\" data-start=\"3244\" data-end=\"3285\">OPSWAT<\/a><\/strong>, even advanced state groups are beginning to use URL files in complex campaigns. They are being used as low-signature tools to initiate attacks &#8211; especially when combined with LNK, HTA and PowerShell strings. <\/p>\n<p data-start=\"3507\" data-end=\"3647\">Instead of creating new malware from scratch, attackers use a simple URL file as the first step to execute a more complex sequence.<\/p>\n<h2 data-start=\"3649\" data-end=\"3698\">How OPSWAT identifies malicious shortcut files<\/h2>\n<p data-start=\"3700\" data-end=\"3802\"><strong data-start=\"3700\" data-end=\"3745\"><a class=\"\" href=\"https:\/\/ramsdata.com.pl\/opswat\/\" target=\"_new\" rel=\"noopener\" data-start=\"3702\" data-end=\"3743\">OPSWAT<\/a><\/strong> uses two tools to fully analyze URL files:<\/p>\n<ul data-start=\"3804\" data-end=\"4149\">\n<li data-start=\"3804\" data-end=\"3940\">\n<p data-start=\"3806\" data-end=\"3940\"><strong data-start=\"3806\" data-end=\"3817\">FileTAC<\/strong> &#8211; for static inspection (DFI &#8211; Deep File Inspection), detects metadata manipulation, hidden values, suspicious fields<\/p>\n<\/li>\n<li data-start=\"3941\" data-end=\"4149\">\n<p data-start=\"3943\" data-end=\"4149\"><strong data-start=\"3943\" data-end=\"3967\">MetaDefender Sandbox<\/strong> &#8211; a dynamic environment that analyzes the operation of a URL file in real time, detecting attempts to connect to external servers, create autostart files, download payloads<\/p>\n<\/li>\n<\/ul>\n<p data-start=\"4151\" data-end=\"4273\">By combining the two approaches, it is possible to fully identify and neutralize the malicious file &#8211; before it has time to do damage.<\/p>\n<h2 data-start=\"4275\" data-end=\"4290\">Summary<\/h2>\n<p data-start=\"4292\" data-end=\"4877\">URL files are no longer innocent shortcuts to sites &#8211; they are becoming a viable threat vector in the cyberattack landscape. Their simplicity makes them attractive to attackers, while users&#8217; inattention and lack of effective analysis tools give them a dangerous window of opportunity. With the help of <strong data-start=\"4572\" data-end=\"4617\"><a class=\"\" href=\"https:\/\/ramsdata.com.pl\/opswat\/\" target=\"_new\" rel=\"noopener\" data-start=\"4574\" data-end=\"4615\">OPSWAT<\/a><\/strong> you can not only detect such files, but also effectively analyze and eliminate them as part of a broader file security strategy. In the next parts of the series, OPSWAT experts will show how to identify threats in URL files at the code and behavioral levels.   <\/p>\n<p data-start=\"4879\" data-end=\"5041\" data-is-last-node=\"\" data-is-only-node=\"\">Want to learn more about OPSWAT&#8217;s malicious file analysis and tools? Check out the offer: <a class=\"\" href=\"https:\/\/ramsdata.com.pl\/opswat\/\" target=\"_new\" rel=\"noopener\" data-start=\"4975\" data-end=\"5041\" data-is-last-node=\"\">https:\/\/ramsdata.com.pl\/opswat.<\/a> <\/p>\n<p data-start=\"4879\" data-end=\"5041\" data-is-last-node=\"\" data-is-only-node=\"\"><img fetchpriority=\"high\" decoding=\"async\" class=\"aligncenter size-full wp-image-38411\" src=\"https:\/\/ramsdata.com.pl\/wp-content\/uploads\/2025\/05\/Ramsdata-5.png\" alt=\"Cyber Security, OPSWAT\" width=\"1000\" height=\"800\" srcset=\"https:\/\/ramsdata.com.pl\/wp-content\/uploads\/2025\/05\/Ramsdata-5.png 1000w, https:\/\/ramsdata.com.pl\/wp-content\/uploads\/2025\/05\/Ramsdata-5-300x240.png 300w, https:\/\/ramsdata.com.pl\/wp-content\/uploads\/2025\/05\/Ramsdata-5-768x614.png 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"aria-live=polite absolute\">\n<div class=\"flex items-center justify-center\"><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Internet shortcut files, or so-called URL files, have for years been regarded as harmless and unimportant parts of Windows. However, they are now becoming increasingly used by cybercriminals and APT groups as part of complex infection chains. Thanks to the simplicity of the format, low detection rate and specific system behavior, URL files are becoming [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":37576,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[56],"tags":[],"class_list":["post-39223","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news-en"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/posts\/39223","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/comments?post=39223"}],"version-history":[{"count":0,"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/posts\/39223\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/media\/37576"}],"wp:attachment":[{"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/media?parent=39223"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/categories?post=39223"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ramsdata.com.pl\/en\/wp-json\/wp\/v2\/tags?post=39223"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}