{"id":15717,"date":"2026-10-14T18:08:03","date_gmt":"2026-10-14T12:38:03","guid":{"rendered":"https:\/\/threatcop.com\/blog\/?p=15717"},"modified":"2026-10-14T18:09:22","modified_gmt":"2026-10-14T12:39:22","slug":"agent-tesla-infostealer","status":"publish","type":"post","link":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/","title":{"rendered":"Agent Tesla Infostealer: How It Works and Defenses"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Agent Tesla is a long-running .NET infostealer that logs keystrokes, steals saved passwords, and sends them to attackers. It has been seen since at least 2014 and is still active. It arrives mostly through phishing emails with attachments that look like invoices or orders. Stopping it means blocking the attachment, limiting what can run, watching outbound traffic, and treating every credential on an infected machine as stolen.<\/p><div id=\"ez-toc-container\" class=\"ez-toc-v2_0_88 ez-toc-wrap-center counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #414141;color:#414141\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #414141;color:#414141\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#What_Agent_Tesla_Is\" >What Agent Tesla Is<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#How_an_Agent_Tesla_Attack_Unfolds\" >How an Agent Tesla Attack Unfolds<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#Book_a_Free_Demo_Call_with_Our_Expert\" >Book a Free Demo Call with Our Expert<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#Why_Stolen_Credentials_Matter_So_Much\" >Why Stolen Credentials Matter So Much<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#What_the_Lure_Looks_Like\" >What the Lure Looks Like<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#Controls_That_Break_the_Chain\" >Controls That Break the Chain<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#If_You_Find_It\" >If You Find It<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#Where_People_Break_the_Chain_First\" >Where People Break the Chain First<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#The_Bottom_Line\" >The Bottom Line<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#Frequently_Asked_Questions\" >Frequently Asked Questions<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Agent_Tesla_Is\"><\/span>What Agent Tesla Is<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/attack.mitre.org\/software\/S0331\/\" rel=\"nofollow noopener\" target=\"_blank\">MITRE ATT&amp;CK<\/a> describes Agent Tesla as a spyware Trojan written for the .NET framework that has been observed since at least 2014. It lists the primary delivery method as email phishing messages with a malicious attachment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So what it steals is broad. MITRE notes that it can log keystrokes, capture screenshots, and gather credentials from browsers, FTP clients, and wireless profiles. It also collects system details, so attackers learn what they have infected.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">CISA lists Agent Tesla among the top malware strains of 2021 and notes that criminals used it for at least five years. It belongs to the malware-as-a-service world, where developers write the malware and distributors sell it on to others. That is why it stays common. A low-skilled criminal can rent a working tool, and it sits alongside other <a href=\"https:\/\/threatcop.com\/blog\/different-types-of-malware\/\">types of malware<\/a> in the same market.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_an_Agent_Tesla_Attack_Unfolds\"><\/span>How an Agent Tesla Attack Unfolds<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Each stage of an attack leaves something a defender can see.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><strong>Stage<\/strong><\/th><th><strong>What happens<\/strong><\/th><th><strong>What to watch<\/strong><\/th><\/tr><\/thead><tbody><tr><td>Lure<\/td><td>An email with an invoice or order attachment arrives<\/td><td>Unexpected attachments, especially from new senders<\/td><\/tr><tr><td>Open<\/td><td>The user opens the attachment<\/td><td>Documents or archives that launch scripts<\/td><\/tr><tr><td>Load<\/td><td>A loader runs and injects the payload into a legitimate process<\/td><td>Process injection, known as process hollowing<\/td><\/tr><tr><td>Hide<\/td><td>The malware obscures its code and stops analysis tools<\/td><td>Security tools that stop unexpectedly<\/td><\/tr><tr><td>Persist<\/td><td>It adds itself to startup entries or scheduled tasks<\/td><td>New registry run keys and scheduled tasks<\/td><\/tr><tr><td>Steal<\/td><td>It collects passwords and keystrokes<\/td><td>Reads of browser and mail credential stores<\/td><\/tr><tr><td>Send<\/td><td>It exfiltrates the data over SMTP, FTP, or HTTP<\/td><td>Outbound mail or file transfer from endpoints<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">MITRE documents each of these behaviors, including process hollowing, persistence through registry and scheduled tasks, and exfiltration over SMTP, FTP, and HTTP. The last row is useful for defenders. An ordinary laptop rarely needs to send mail or upload files by itself. Attachments are also not limited to Office files, since PDFs can deliver malware too.<\/p>\n\n\n\n<meta charset=\"UTF-8\">\n<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n<title>Threatcop \u2013 Book a Free Demo<\/title>\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Outfit:wght@300;400;500;600;700&#038;display=swap\" rel=\"stylesheet\">\n<style>\n  .tc-wrap , .tc-wrap ::before, .tc-wrap ::after { box-sizing: border-box; margin: 0; padding: 0; }\n  .tc-wrap { font-family: 'Outfit', sans-serif; width: 100%; display: flex; justify-content: center; padding: 20px 10px; }\n  .tc-card { width: 100%; max-width: 820px; background: #fff; border-radius: 20px; overflow: hidden; box-shadow: 0 20px 60px rgba(24,57,148,0.13), 0 4px 16px rgba(24,57,148,0.07); display: flex; flex-direction: row; }\n  .tc-left { background: linear-gradient(160deg, #1e44b0 0%, #183994 40%, #0e2570 100%); width: 320px; flex-shrink: 0; padding: 40px 32px; display: flex; flex-direction: column; justify-content: center; position: relative; overflow: hidden; }\n  .tc-left::before { content: ''; position: absolute; inset: 0; background-image: radial-gradient(rgba(255,255,255,0.08) 1.5px, transparent 1.5px); background-size: 22px 22px; }\n  .tc-left::after { content: ''; position: absolute; bottom: -60px; right: -60px; width: 220px; height: 220px; background: radial-gradient(circle, rgba(99,179,255,0.22) 0%, transparent 65%); border-radius: 50%; pointer-events: none; }\n  .tc-panel-inner { position: relative; z-index: 1; }\n  .tc-badge { display: inline-flex !important; align-items: center !important; gap: 6px; background: rgba(255,255,255,0.1) !important; border: 1px solid rgba(255,255,255,0.18) !important; border-radius: 20px !important; padding: 4px 14px 4px 10px !important; font-size: 12.5px !important; font-weight: 600 !important; letter-spacing: .09em !important; text-transform: uppercase !important; color: rgba(255,255,255,0.85) !important; margin-bottom: 18px !important; font-family: 'Outfit', sans-serif !important; line-height: 1.4 !important; }\n  .tc-badge-dot { width: 6px; height: 6px; background: #5cd9a0; border-radius: 50%; box-shadow: 0 0 6px #5cd9a0; flex-shrink: 0; display: inline-block; }\n  .tc-left h1, .tc-left h2, .tc-left h3, .tc-left h4, .tc-left h5, .tc-left h6 { color: #ffffff !important; font-family: 'Outfit', sans-serif !important; font-size: 28px !important; font-weight: 700 !important; line-height: 1.35 !important; letter-spacing: -0.3px !important; margin: 0 !important; padding: 0 !important; background: none !important; -webkit-text-fill-color: #ffffff !important; }\n  .tc-left h2 em { font-style: normal !important; color: #7ec8ff !important; -webkit-text-fill-color: #7ec8ff !important; }\n  .tc-left p, .tc-left .tc-sub { color: rgba(255,255,255,0.78) !important; -webkit-text-fill-color: rgba(255,255,255,0.78) !important; font-family: 'Outfit', sans-serif !important; font-size: 14px !important; font-weight: 300 !important; line-height: 1.65 !important; margin-top: 12px !important; background: none !important; }\n  .tc-right { flex: 1; padding: 32px 32px 28px; display: flex; flex-direction: column; justify-content: center; }\n  .tc-form-title { font-size: 13px !important; font-weight: 600 !important; letter-spacing: .12em; text-transform: uppercase; color: #8fa4cc !important; margin-bottom: 20px !important; display: flex !important; align-items: center !important; gap: 10px; font-family: 'Outfit', sans-serif !important; }\n  .tc-form-title::after { content: ''; flex: 1; height: 1px; background: #eef1fa; }\n  .tc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }\n  .tc-field { display: flex; flex-direction: column; gap: 5px; }\n  .tc-field.full { grid-column: 1 \/ -1; }\n  .tc-field label { font-size: 13px !important; font-weight: 600 !important; color: #3a4f7a !important; letter-spacing: .04em; text-transform: uppercase; font-family: 'Outfit', sans-serif !important; display: block !important; }\n  .tc-input-wrap { position: relative; display: flex; align-items: center; }\n  .tc-input-wrap .tc-fi { position: absolute; right: 12px; width: 15px; height: 15px; stroke: #c0ccdf; stroke-width: 1.8; pointer-events: none; fill: none; }\n  .tc-wrap input[type=\"text\"], .tc-wrap input[type=\"email\"], .tc-wrap input[type=\"number\"] { width: 100% !important; border: 1.5px solid #e2e9f7 !important; border-radius: 10px !important; padding: 9px 34px 9px 13px !important; font-family: 'Outfit', sans-serif !important; font-size: 15px !important; font-weight: 400 !important; color: #1e2d50 !important; background: #f8faff !important; outline: none !important; transition: border-color .2s, background .2s, box-shadow .2s; -moz-appearance: textfield; box-shadow: none !important; -webkit-text-fill-color: #1e2d50 !important; }\n  .tc-wrap input[type=\"number\"]::-webkit-inner-spin-button, .tc-wrap input[type=\"number\"]::-webkit-outer-spin-button { -webkit-appearance: none; }\n  .tc-wrap input::placeholder { color: #c0ccdf !important; -webkit-text-fill-color: #c0ccdf !important; opacity: 1; }\n  .tc-wrap input:focus { border-color: #183994 !important; background: #fff !important; box-shadow: 0 0 0 3.5px rgba(24,57,148,0.1) !important; }\n  .tc-phone-row { display: flex; gap: 8px; }\n  .tc-flag-select { position: relative; flex-shrink: 0; }\n  .tc-flag-select select { appearance: none !important; -webkit-appearance: none !important; border: 1.5px solid #e2e9f7 !important; border-radius: 10px !important; padding: 9px 26px 9px 12px !important; font-family: 'Outfit', sans-serif !important; font-size: 14px !important; font-weight: 500 !important; color: #1e2d50 !important; background: #f8faff !important; outline: none !important; cursor: pointer; width: 100px !important; transition: border-color .2s, box-shadow .2s; }\n  .tc-flag-select select:focus { border-color: #183994 !important; box-shadow: 0 0 0 3.5px rgba(24,57,148,0.1) !important; }\n  .tc-flag-select::after { content: ''; position: absolute; right: 10px; top: 50%; transform: translateY(-50%); width: 0; height: 0; border-left: 4px solid transparent; border-right: 4px solid transparent; border-top: 5px solid #a0b0cc; pointer-events: none; }\n  .tc-phone-row .tc-input-wrap { flex: 1; }\n  .tc-btn-submit { width: 100% !important; margin-top: 18px !important; padding: 11px !important; background: #183994 !important; border: none !important; border-radius: 10px !important; color: #fff !important; -webkit-text-fill-color: #fff !important; font-family: 'Outfit', sans-serif !important; font-size: 15px !important; font-weight: 600 !important; letter-spacing: .05em; cursor: pointer; display: flex !important; align-items: center !important; justify-content: center !important; gap: 9px; transition: background .2s, transform .15s, box-shadow .2s; box-shadow: 0 6px 24px rgba(24,57,148,0.28) !important; text-decoration: none !important; }\n  .tc-btn-submit:hover { background: #1d46b5 !important; transform: translateY(-1px); box-shadow: 0 10px 32px rgba(24,57,148,0.35) !important; color: #fff !important; }\n  .tc-btn-submit:active { transform: translateY(0); }\n  .tc-btn-submit svg { width: 16px; height: 16px; stroke: #fff; stroke-width: 2.2; fill: none; flex-shrink: 0; }\n  .tc-trust { margin-top: 10px !important; display: flex !important; align-items: center !important; justify-content: center !important; gap: 5px; font-size: 13px !important; color: #a0b0cc !important; font-family: 'Outfit', sans-serif !important; }\n  .tc-trust svg { width: 12px; height: 12px; stroke: #a0b0cc; stroke-width: 2; fill: none; flex-shrink: 0; }\n  @media (max-width: 680px) {\n    .tc-card { flex-direction: column !important; }\n    .tc-left { width: 100% !important; padding: 28px 24px 24px !important; }\n    .tc-right { padding: 24px 20px !important; }\n    .tc-grid { grid-template-columns: 1fr !important; }\n    .tc-field.full { grid-column: 1 !important; }\n  }\n<\/style>\n\n<div class=\"tc-wrap\">\n  <div class=\"tc-card\">\n    <div class=\"tc-left\">\n      <div class=\"tc-panel-inner\">\n        <div class=\"tc-badge\">\n          <span class=\"tc-badge-dot\"><\/span>\n          People Security Management\n        <\/div>\n        <h2><span class=\"ez-toc-section\" id=\"Book_a_Free_Demo_Call_with_Our_Expert\"><\/span>Book a Free<br><em>Demo Call<\/em><br>with Our Expert<span class=\"ez-toc-section-end\"><\/span><\/h2>\n        <p class=\"tc-sub\">Discover how Threatcop protects your workforce from modern cyber threats.<\/p>\n      <\/div>\n    <\/div>\n    <div class=\"tc-right\">\n      <div class=\"tc-form-title\">Your Details<\/div>\n      <form action=\"https:\/\/threatcop.com\/thankyou-blog\" method=\"get\" target=\"_blank\">\n        <input type=\"hidden\" name=\"BlogForm\" value=\"BlogForm\">\n        <input type=\"hidden\" name=\"PageSource\" id=\"tc-page-source\" value=\"\">\n        <div class=\"tc-grid\">\n          <div class=\"tc-field\">\n            <label>Full Name<\/label>\n            <div class=\"tc-input-wrap\">\n              <input type=\"text\" name=\"FullName\" placeholder=\"Jane Smith\" required=\"\">\n              <svg class=\"tc-fi\" viewBox=\"0 0 24 24\" stroke-linecap=\"round\"><circle cx=\"12\" cy=\"8\" r=\"4\"><\/circle><path d=\"M4 20c0-4 3.58-7 8-7s8 3 8 7\"><\/path><\/svg>\n            <\/div>\n          <\/div>\n          <div class=\"tc-field\">\n            <label>Company Name<\/label>\n            <div class=\"tc-input-wrap\">\n              <input type=\"text\" name=\"CompanyName\" placeholder=\"Acme Corp\" required=\"\">\n              <svg class=\"tc-fi\" viewBox=\"0 0 24 24\" stroke-linecap=\"round\"><rect x=\"3\" y=\"3\" width=\"18\" height=\"18\" rx=\"2\"><\/rect><path d=\"M9 3v18M3 9h6M3 15h6\"><\/path><\/svg>\n            <\/div>\n          <\/div>\n          <div class=\"tc-field full\">\n            <label>Corporate Email<\/label>\n            <div class=\"tc-input-wrap\">\n              <input type=\"email\" name=\"email\" placeholder=\"jane@yourcompany.com\" required=\"\">\n              <svg class=\"tc-fi\" viewBox=\"0 0 24 24\" stroke-linecap=\"round\"><rect x=\"2\" y=\"4\" width=\"20\" height=\"16\" rx=\"2\"><\/rect><polyline points=\"2,4 12,13 22,4\"><\/polyline><\/svg>\n            <\/div>\n          <\/div>\n          <div class=\"tc-field full\">\n            <label>Phone Number<\/label>\n            <div class=\"tc-input-wrap\">\n              <input type=\"number\" name=\"Phone\" placeholder=\"98765 43210\" required=\"\">\n              <svg class=\"tc-fi\" viewBox=\"0 0 24 24\" stroke-linecap=\"round\"><path d=\"M22 16.92v3a2 2 0 01-2.18 2A19.79 19.79 0 013.09 4.18 2 2 0 015.07 2h3a2 2 0 012 1.72c.13.96.36 1.9.71 2.81a2 2 0 01-.45 2.11L9.09 9.91a16 16 0 006 6l1.27-1.27a2 2 0 012.11-.45c.91.35 1.85.58 2.81.71A2 2 0 0122 16.92z\"><\/path><\/svg>\n            <\/div>\n          <\/div>\n        <\/div>\n        <button type=\"submit\" class=\"tc-btn-submit\">\n          <svg viewBox=\"0 0 24 24\" stroke-linecap=\"round\"><path d=\"M22 2L11 13M22 2L15 22l-4-9-9-4 20-7z\"><\/path><\/svg>\n          Book My Free Demo\n        <\/button>\n        <div class=\"tc-trust\">\n          <svg viewBox=\"0 0 24 24\" stroke-linecap=\"round\"><rect x=\"3\" y=\"11\" width=\"18\" height=\"11\" rx=\"2\"><\/rect><path d=\"M7 11V7a5 5 0 0110 0v4\"><\/path><\/svg>\n          Your data is safe &amp; never shared with third parties\n        <\/div>\n      <\/form>\n    <\/div>\n  <\/div>\n<\/div>\n<script>document.getElementById('tc-page-source').value = window.location.href;<\/script>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Why_Stolen_Credentials_Matter_So_Much\"><\/span>Why Stolen Credentials Matter So Much<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">An infostealer is rarely the end of the attack. Instead, it is the supply line. Stolen mail logins let an attacker read a mailbox, learn who pays whom, and send convincing requests. Stolen browser passwords open cloud services and VPNs.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is why an Agent Tesla infection should never be treated as a single-machine problem. The data it takes can be used days later, from a different place. <a href=\"https:\/\/threatcop.com\/blog\/credential-harvesting\/\">Credential harvesting<\/a> of this kind fuels much of the fraud seen in business email compromise cases.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">MITRE lists TA2541 and SilverTerrier among the groups that use Agent Tesla. It shows how a commodity tool serves more than one kind of criminal.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_the_Lure_Looks_Like\"><\/span>What the Lure Looks Like<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">MITRE lists email phishing with a malicious attachment as the primary delivery method. So the lure is the first place to stop an Agent Tesla attack. These are common signs, and staff can learn them in minutes.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>An invoice, order, or payroll notice nobody expected.<\/strong> Ask, &#8220;Was I expecting this?&#8221;<\/li>\n\n\n\n<li><strong>A sender you do not know, or a lookalike of one you do.<\/strong> Check the full address, not the display name.<\/li>\n\n\n\n<li><strong>Urgency or a request to open the file now.<\/strong> Pressure is a standard attacker tool.<\/li>\n\n\n\n<li><strong>An attachment type that does not fit the message.<\/strong> An invoice that arrives as an archive or script file is suspicious.<\/li>\n\n\n\n<li><strong>A reply-to address that differs from the sender.<\/strong> Replies would go somewhere else.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If any sign appears, do not open the file. Report it instead.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Controls_That_Break_the_Chain\"><\/span>Controls That Break the Chain<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">No single control stops Agent Tesla. Layer controls so that one missed step does not end in a loss.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Handle risky attachments carefully.<\/strong> Block or sandbox executable and script attachments, and remember that the attachment need not be an Office file.<\/li>\n\n\n\n<li><strong>Limit script execution.<\/strong> Most users never need to run script files from email. Restrict them where you can.<\/li>\n\n\n\n<li><strong>Use endpoint detection.<\/strong> It can catch process injection and persistence tricks that antivirus misses.<\/li>\n\n\n\n<li><strong>Control outbound traffic.<\/strong> Block SMTP and FTP from endpoints that have no reason to use them.<\/li>\n\n\n\n<li><strong>Keep passwords out of browsers.<\/strong> Use a password manager, and require MFA so a stolen password is not enough.<\/li>\n\n\n\n<li><strong>Patch and back up.<\/strong> CISA&#8217;s mitigation list for these strains includes <a href=\"https:\/\/www.cisa.gov\/news-events\/cybersecurity-advisories\/aa22-216a\" rel=\"nofollow noopener\" target=\"_blank\">patching, user training, and MFA<\/a>.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"If_You_Find_It\"><\/span>If You Find It<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">After an Agent Tesla infection, assume the worst about what the machine held. The steps below are in order.<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Isolate the device<\/strong> from the network.<\/li>\n\n\n\n<li><strong>Treat every saved or typed credential as stolen.<\/strong> Reset them from a clean device.<\/li>\n\n\n\n<li><strong>Revoke active sessions<\/strong> for the affected accounts, and require MFA again.<\/li>\n\n\n\n<li><strong>Check mailbox rules and forwarding<\/strong> for signs of attacker changes.<\/li>\n\n\n\n<li><strong>Review outbound connections<\/strong> from the device to find where the data went.<\/li>\n\n\n\n<li><strong>Find other recipients<\/strong> of the same email, and remove it from their mailboxes.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Where_People_Break_the_Chain_First\"><\/span>Where People Break the Chain First<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Agent Tesla needs a person to open the attachment. That also gives a person the chance to stop it, though. A staff member who finds an invoice they did not expect, and reports it instead of opening it, ends the attack at step one.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/threatcop.com\/threatcop-phishing-incident-response\">Threatcop Phishing Incident Response (TPIR)<\/a> makes that report a one-click action from email or WhatsApp. Employees can check a message&#8217;s threat level before they decide. TPIR then runs header analysis, link and attachment scanning, an IP reputation check, and fake domain checks in a sandbox. So the security team gets an assessment of the attachment rather than a guess.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Its &#8220;Who Else&#8221; insight then shows which other mailboxes received the same message. Genuine mail returns to the inbox, and TPIR deletes malicious mail. Because infostealer campaigns go out in bulk, removing the message from every inbox matters as much as the first report.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"The_Bottom_Line\"><\/span>The Bottom Line<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Agent Tesla is old, cheap, and effective, which is why it lasts. It works because someone opens an attachment, and it pays off because the stolen logins get used elsewhere. So defend each step. Block and sandbox risky attachments. Limit scripts and outbound mail from endpoints. Keep passwords out of browsers and protect accounts with MFA. When it appears, treat the whole machine as breached and reset every credential it held. Finally, give staff a one-click way to report the invoice they did not expect, because that report stops the chain before the malware ever runs.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Frequently_Asked_Questions\"><\/span>Frequently Asked Questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\t\t<div class=\"sp-easy-accordion-block sp-eab-regular-accordion alignwide\"\n\t\t\t\t>\n\t\t\t<div class=\"sp-eab-wrapper sp-eab-vertical-accordion sp-eab-ff4d242d24d6\">\n\t\t\t\t\t\t\t\t<div class='sp-eab-accordion sp-eab-mode-vertical sp-eab-vertical-one sp-d-flex' data-accordion-settings=\"{&quot;mode&quot;:&quot;vertical&quot;,&quot;activeEvent&quot;:&quot;click&quot;,&quot;defaultAccordionOpen&quot;:&quot;first-item&quot;,&quot;selectedItemOpen&quot;:0,&quot;openMultiItemAtaTime&quot;:false,&quot;scrollToTopOnLoad&quot;:false,&quot;scrollToTopOnClick&quot;:false,&quot;accordionItemToUrl&quot;:false,&quot;animationEffect&quot;:false,&quot;applyAccessibility&quot;:true}\">\n        \t    \t\n\t\t\t<div\n\t\t\t\tid =\"sp-eab-item-6c863bffa4dc\"\n\t\t\t\tclass=\"sp-eab-accordion-item eab-item-2d24d6\"\n\t\t\t\t\t\t\t>\n\t\t\t\t<div class=\"sp-eab-accordion-item-wrapper\">\n\t\t\t\t\t\t\t\t<h3 class='sp-eab-accordion-heading sp-d-flex sp-align-center eab-heading-2d24d6'\n\t\t\t\t\t\t>\n\t\t\t\t<span class='sp-eab-accordion-header-wrapper sp-d-flex sp-align-center eab-icon-position-end'>\n\t\t\t\t\t<span class='sp-eab-accordion-header-start sp-d-flex sp-justify-left sp-align-center'>\n\t\t\t\t\t\t<span class='sp-eab-title-subtitle-wrapper sp-d-flex'>\n\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-wrapper sp-d-flex sp-align-center'>\n\t\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-text'>\n\t\t\t\t\t\t\t\t\tWhat is Agent Tesla?\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<span class='sp-eab-accordion-header-end eab-icon-animated'>\n\t\t\t\t\t\t\t\t\t\t\t\t<span class='sp-eab-expand-collapse-icon sp-d-block'>\n\t\t\t\t\t\t\t<i class='sp-eab-expand-icon eab-icon-angle-down-solid'><\/i>\n\t\t\t\t\t\t\t<i class='sp-eab-collapse-icon eab-icon-angle-up-solid'><\/i>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t<\/span>\n\t\t\t<\/h3>\n\t\t\t\t\t\t\t<!-- accordion body -->\n\t\t\t\t\t<div class='sp-eab-accordion-content eab-content-2d24d6'>\n\t\t\t\t\t\t\t\t\t\t\t\t<div class='sp-eab-accordion-content-wrapper'>\n\t\t\t\t\t\t\t<div class='sp-eab-accordion-body'>\n\t\t\t    \t\t\t\t\n\n<p class=\"wp-block-paragraph\">Agent Tesla is a .NET spyware Trojan and infostealer, observed since at least 2014. It logs keystrokes, captures screenshots, and steals saved credentials from browsers and other applications. Attackers sell and rent it, so many different criminals use it.<\/p>\n\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\n\n\t\t\t<div\n\t\t\t\tid =\"sp-eab-item-0bf426d2f2bc\"\n\t\t\t\tclass=\"sp-eab-accordion-item eab-item-2d24d6\"\n\t\t\t\t\t\t\t>\n\t\t\t\t<div class=\"sp-eab-accordion-item-wrapper\">\n\t\t\t\t\t\t\t\t<h3 class='sp-eab-accordion-heading sp-d-flex sp-align-center eab-heading-2d24d6'\n\t\t\t\t\t\t>\n\t\t\t\t<span class='sp-eab-accordion-header-wrapper sp-d-flex sp-align-center eab-icon-position-end'>\n\t\t\t\t\t<span class='sp-eab-accordion-header-start sp-d-flex sp-justify-left sp-align-center'>\n\t\t\t\t\t\t<span class='sp-eab-title-subtitle-wrapper sp-d-flex'>\n\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-wrapper sp-d-flex sp-align-center'>\n\t\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-text'>\n\t\t\t\t\t\t\t\t\tHow is Agent Tesla delivered?\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<span class='sp-eab-accordion-header-end eab-icon-animated'>\n\t\t\t\t\t\t\t\t\t\t\t\t<span class='sp-eab-expand-collapse-icon sp-d-block'>\n\t\t\t\t\t\t\t<i class='sp-eab-expand-icon eab-icon-angle-down-solid'><\/i>\n\t\t\t\t\t\t\t<i class='sp-eab-collapse-icon eab-icon-angle-up-solid'><\/i>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t<\/span>\n\t\t\t<\/h3>\n\t\t\t\t\t\t\t<!-- accordion body -->\n\t\t\t\t\t<div class='sp-eab-accordion-content eab-content-2d24d6'>\n\t\t\t\t\t\t\t\t\t\t\t\t<div class='sp-eab-accordion-content-wrapper'>\n\t\t\t\t\t\t\t<div class='sp-eab-accordion-body'>\n\t\t\t    \t\t\t\t\n\n<p class=\"wp-block-paragraph\">MITRE lists email phishing with a malicious attachment as its primary delivery method. The email often looks like an invoice, purchase order, or payroll notice. The attachment launches the infection when a user opens it. Learning to <a href=\"https:\/\/threatcop.com\/blog\/how-to-recognize-phishing-emails\/\">recognize phishing emails<\/a> helps stop that step.<\/p>\n\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\n\n\t\t\t<div\n\t\t\t\tid =\"sp-eab-item-1a06b3121d7c\"\n\t\t\t\tclass=\"sp-eab-accordion-item eab-item-2d24d6\"\n\t\t\t\t\t\t\t>\n\t\t\t\t<div class=\"sp-eab-accordion-item-wrapper\">\n\t\t\t\t\t\t\t\t<h3 class='sp-eab-accordion-heading sp-d-flex sp-align-center eab-heading-2d24d6'\n\t\t\t\t\t\t>\n\t\t\t\t<span class='sp-eab-accordion-header-wrapper sp-d-flex sp-align-center eab-icon-position-end'>\n\t\t\t\t\t<span class='sp-eab-accordion-header-start sp-d-flex sp-justify-left sp-align-center'>\n\t\t\t\t\t\t<span class='sp-eab-title-subtitle-wrapper sp-d-flex'>\n\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-wrapper sp-d-flex sp-align-center'>\n\t\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-text'>\n\t\t\t\t\t\t\t\t\tWhat does Agent Tesla steal?\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<span class='sp-eab-accordion-header-end eab-icon-animated'>\n\t\t\t\t\t\t\t\t\t\t\t\t<span class='sp-eab-expand-collapse-icon sp-d-block'>\n\t\t\t\t\t\t\t<i class='sp-eab-expand-icon eab-icon-angle-down-solid'><\/i>\n\t\t\t\t\t\t\t<i class='sp-eab-collapse-icon eab-icon-angle-up-solid'><\/i>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t<\/span>\n\t\t\t<\/h3>\n\t\t\t\t\t\t\t<!-- accordion body -->\n\t\t\t\t\t<div class='sp-eab-accordion-content eab-content-2d24d6'>\n\t\t\t\t\t\t\t\t\t\t\t\t<div class='sp-eab-accordion-content-wrapper'>\n\t\t\t\t\t\t\t<div class='sp-eab-accordion-body'>\n\t\t\t    \t\t\t\t\n\n<p class=\"wp-block-paragraph\">Agent Tesla steals keystrokes, screenshots, and saved credentials from browsers, FTP clients, and wireless profiles. It also gathers details about the infected system. Attackers then use the stolen logins for fraud, account access, or further attacks.<\/p>\n\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\n\n\t\t\t<div\n\t\t\t\tid =\"sp-eab-item-b2bda3dd3199\"\n\t\t\t\tclass=\"sp-eab-accordion-item eab-item-2d24d6\"\n\t\t\t\t\t\t\t>\n\t\t\t\t<div class=\"sp-eab-accordion-item-wrapper\">\n\t\t\t\t\t\t\t\t<h3 class='sp-eab-accordion-heading sp-d-flex sp-align-center eab-heading-2d24d6'\n\t\t\t\t\t\t>\n\t\t\t\t<span class='sp-eab-accordion-header-wrapper sp-d-flex sp-align-center eab-icon-position-end'>\n\t\t\t\t\t<span class='sp-eab-accordion-header-start sp-d-flex sp-justify-left sp-align-center'>\n\t\t\t\t\t\t<span class='sp-eab-title-subtitle-wrapper sp-d-flex'>\n\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-wrapper sp-d-flex sp-align-center'>\n\t\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-text'>\n\t\t\t\t\t\t\t\t\tHow do you detect Agent Tesla?\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<span class='sp-eab-accordion-header-end eab-icon-animated'>\n\t\t\t\t\t\t\t\t\t\t\t\t<span class='sp-eab-expand-collapse-icon sp-d-block'>\n\t\t\t\t\t\t\t<i class='sp-eab-expand-icon eab-icon-angle-down-solid'><\/i>\n\t\t\t\t\t\t\t<i class='sp-eab-collapse-icon eab-icon-angle-up-solid'><\/i>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t<\/span>\n\t\t\t<\/h3>\n\t\t\t\t\t\t\t<!-- accordion body -->\n\t\t\t\t\t<div class='sp-eab-accordion-content eab-content-2d24d6'>\n\t\t\t\t\t\t\t\t\t\t\t\t<div class='sp-eab-accordion-content-wrapper'>\n\t\t\t\t\t\t\t<div class='sp-eab-accordion-body'>\n\t\t\t    \t\t\t\t\n\n<p class=\"wp-block-paragraph\">Watch for process injection, new registry run keys or scheduled tasks, and endpoints sending mail or uploading files over SMTP, FTP, or HTTP. Endpoint detection tools can catch these behaviors, and staff reports can catch the lure before it runs.<\/p>\n\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\n\n\t\t\t<div\n\t\t\t\tid =\"sp-eab-item-5e08a25bb941\"\n\t\t\t\tclass=\"sp-eab-accordion-item eab-item-2d24d6\"\n\t\t\t\t\t\t\t>\n\t\t\t\t<div class=\"sp-eab-accordion-item-wrapper\">\n\t\t\t\t\t\t\t\t<h3 class='sp-eab-accordion-heading sp-d-flex sp-align-center eab-heading-2d24d6'\n\t\t\t\t\t\t>\n\t\t\t\t<span class='sp-eab-accordion-header-wrapper sp-d-flex sp-align-center eab-icon-position-end'>\n\t\t\t\t\t<span class='sp-eab-accordion-header-start sp-d-flex sp-justify-left sp-align-center'>\n\t\t\t\t\t\t<span class='sp-eab-title-subtitle-wrapper sp-d-flex'>\n\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-wrapper sp-d-flex sp-align-center'>\n\t\t\t\t\t\t\t\t<span class='sp-eab-accordion-title-text'>\n\t\t\t\t\t\t\t\t\tWhat should you do after an Agent Tesla infection?\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<span class='sp-eab-accordion-header-end eab-icon-animated'>\n\t\t\t\t\t\t\t\t\t\t\t\t<span class='sp-eab-expand-collapse-icon sp-d-block'>\n\t\t\t\t\t\t\t<i class='sp-eab-expand-icon eab-icon-angle-down-solid'><\/i>\n\t\t\t\t\t\t\t<i class='sp-eab-collapse-icon eab-icon-angle-up-solid'><\/i>\n\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t<\/span>\n\t\t\t<\/h3>\n\t\t\t\t\t\t\t<!-- accordion body -->\n\t\t\t\t\t<div class='sp-eab-accordion-content eab-content-2d24d6'>\n\t\t\t\t\t\t\t\t\t\t\t\t<div class='sp-eab-accordion-content-wrapper'>\n\t\t\t\t\t\t\t<div class='sp-eab-accordion-body'>\n\t\t\t    \t\t\t\t\n\n<p class=\"wp-block-paragraph\">Isolate the device, then treat every credential on it as stolen and reset them from a clean device. Revoke active sessions, check mailbox rules, review outbound connections, and remove the original email from other mailboxes. Handling it as a credential breach, not a single infection, limits the damage.<\/p>\n\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Agent Tesla steals passwords and keystrokes through phishing attachments. See how an attack unfolds, which controls break the chain, and how to respond.<\/p>\n","protected":false},"author":22,"featured_media":15724,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[41],"tags":[],"class_list":["post-15717","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cyber-attacks"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Agent Tesla Infostealer: How It Works and Defenses<\/title>\n<meta name=\"description\" content=\"Agent Tesla steals passwords and keystrokes through phishing attachments. See how an attack unfolds, which controls break the chain, and how to respond.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Agent Tesla Infostealer: How It Works and Defenses\" \/>\n<meta property=\"og:description\" content=\"Agent Tesla steals passwords and keystrokes through phishing attachments. See how an attack unfolds, which controls break the chain, and how to respond.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/\" \/>\n<meta property=\"og:site_name\" content=\"Threatcop\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/people\/Threatcop\/100083109892339\/\" \/>\n<meta property=\"article:published_time\" content=\"2026-10-14T12:38:03+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-10-14T12:39:22+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/10\/Agent-Tesla-Infostealer-blog-banner.png\" \/>\n\t<meta property=\"og:image:width\" content=\"1280\" \/>\n\t<meta property=\"og:image:height\" content=\"720\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"Shikha Mishra\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@threatcop\" \/>\n<meta name=\"twitter:site\" content=\"@threatcop\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Shikha Mishra\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/\"},\"author\":{\"name\":\"Shikha Mishra\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#\\\/schema\\\/person\\\/b726b18845470084a82f5fed6875910b\"},\"headline\":\"Agent Tesla Infostealer: How It Works and Defenses\",\"datePublished\":\"2026-10-14T12:38:03+00:00\",\"dateModified\":\"2026-10-14T12:39:22+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/\"},\"wordCount\":1337,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/10\\\/Agent-Tesla-Infostealer-blog-banner.png\",\"articleSection\":[\"Cyber Attacks\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/\",\"url\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/\",\"name\":\"Agent Tesla Infostealer: How It Works and Defenses\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/10\\\/Agent-Tesla-Infostealer-blog-banner.png\",\"datePublished\":\"2026-10-14T12:38:03+00:00\",\"dateModified\":\"2026-10-14T12:39:22+00:00\",\"description\":\"Agent Tesla steals passwords and keystrokes through phishing attachments. See how an attack unfolds, which controls break the chain, and how to respond.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#primaryimage\",\"url\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/10\\\/Agent-Tesla-Infostealer-blog-banner.png\",\"contentUrl\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/10\\\/Agent-Tesla-Infostealer-blog-banner.png\",\"width\":1280,\"height\":720,\"caption\":\"Threatcop blog banner reading Agent Tesla Infostealer, How It Works and Defenses, over an abstract network graph on a dark navy background\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/agent-tesla-infostealer\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Agent Tesla Infostealer: How It Works and Defenses\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/\",\"name\":\"Threatcop\",\"description\":\"Cybersecurity Blogs, News, Updates, and Articles\",\"publisher\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#organization\",\"name\":\"Threatcop\",\"url\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/threatcop-logo-black-1.png\",\"contentUrl\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/threatcop-logo-black-1.png\",\"width\":432,\"height\":102,\"caption\":\"Threatcop\"},\"image\":{\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/people\\\/Threatcop\\\/100083109892339\\\/\",\"https:\\\/\\\/x.com\\\/threatcop\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/threatcop\\\/\",\"https:\\\/\\\/www.instagram.com\\\/threatcop_official\\\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/#\\\/schema\\\/person\\\/b726b18845470084a82f5fed6875910b\",\"name\":\"Shikha Mishra\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/08\\\/avatar_user_22_1756470936.png\",\"url\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/08\\\/avatar_user_22_1756470936.png\",\"contentUrl\":\"https:\\\/\\\/threatcop.com\\\/blog\\\/wp-content\\\/uploads\\\/2025\\\/08\\\/avatar_user_22_1756470936.png\",\"caption\":\"Shikha Mishra\"},\"description\":\"Shikha Mishra is responsible for driving the growth and adoption of TDMARC, a flagship product of Threatcop, across India, the Middle East, APAC, and the UK region. With her expertise, she helps organizations safeguard their domains so that no hacker can misuse them to send fraudulent emails, thereby protecting both their brand and reputation. She is passionate about enabling businesses to simplify the complexities of outbound email security through TDMARC\u2019s comprehensive solution, allowing them to stay focused on what matters most to their success.\",\"sameAs\":[\"https:\\\/\\\/threatcop.com\\\/\",\"https:\\\/\\\/www.linkedin.com\\\/in\\\/shikha-mishra-9594771b5\\\/\"]}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Agent Tesla Infostealer: How It Works and Defenses","description":"Agent Tesla steals passwords and keystrokes through phishing attachments. See how an attack unfolds, which controls break the chain, and how to respond.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/","og_locale":"en_US","og_type":"article","og_title":"Agent Tesla Infostealer: How It Works and Defenses","og_description":"Agent Tesla steals passwords and keystrokes through phishing attachments. See how an attack unfolds, which controls break the chain, and how to respond.","og_url":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/","og_site_name":"Threatcop","article_publisher":"https:\/\/www.facebook.com\/people\/Threatcop\/100083109892339\/","article_published_time":"2026-10-14T12:38:03+00:00","article_modified_time":"2026-10-14T12:39:22+00:00","og_image":[{"width":1280,"height":720,"url":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/10\/Agent-Tesla-Infostealer-blog-banner.png","type":"image\/png"}],"author":"Shikha Mishra","twitter_card":"summary_large_image","twitter_creator":"@threatcop","twitter_site":"@threatcop","twitter_misc":{"Written by":"Shikha Mishra","Est. reading time":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#article","isPartOf":{"@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/"},"author":{"name":"Shikha Mishra","@id":"https:\/\/threatcop.com\/blog\/#\/schema\/person\/b726b18845470084a82f5fed6875910b"},"headline":"Agent Tesla Infostealer: How It Works and Defenses","datePublished":"2026-10-14T12:38:03+00:00","dateModified":"2026-10-14T12:39:22+00:00","mainEntityOfPage":{"@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/"},"wordCount":1337,"commentCount":0,"publisher":{"@id":"https:\/\/threatcop.com\/blog\/#organization"},"image":{"@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#primaryimage"},"thumbnailUrl":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/10\/Agent-Tesla-Infostealer-blog-banner.png","articleSection":["Cyber Attacks"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/","url":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/","name":"Agent Tesla Infostealer: How It Works and Defenses","isPartOf":{"@id":"https:\/\/threatcop.com\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#primaryimage"},"image":{"@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#primaryimage"},"thumbnailUrl":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/10\/Agent-Tesla-Infostealer-blog-banner.png","datePublished":"2026-10-14T12:38:03+00:00","dateModified":"2026-10-14T12:39:22+00:00","description":"Agent Tesla steals passwords and keystrokes through phishing attachments. See how an attack unfolds, which controls break the chain, and how to respond.","breadcrumb":{"@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#primaryimage","url":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/10\/Agent-Tesla-Infostealer-blog-banner.png","contentUrl":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/10\/Agent-Tesla-Infostealer-blog-banner.png","width":1280,"height":720,"caption":"Threatcop blog banner reading Agent Tesla Infostealer, How It Works and Defenses, over an abstract network graph on a dark navy background"},{"@type":"BreadcrumbList","@id":"https:\/\/threatcop.com\/blog\/agent-tesla-infostealer\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/threatcop.com\/blog\/"},{"@type":"ListItem","position":2,"name":"Agent Tesla Infostealer: How It Works and Defenses"}]},{"@type":"WebSite","@id":"https:\/\/threatcop.com\/blog\/#website","url":"https:\/\/threatcop.com\/blog\/","name":"Threatcop","description":"Cybersecurity Blogs, News, Updates, and Articles","publisher":{"@id":"https:\/\/threatcop.com\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/threatcop.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/threatcop.com\/blog\/#organization","name":"Threatcop","url":"https:\/\/threatcop.com\/blog\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/threatcop.com\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/08\/threatcop-logo-black-1.png","contentUrl":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2026\/08\/threatcop-logo-black-1.png","width":432,"height":102,"caption":"Threatcop"},"image":{"@id":"https:\/\/threatcop.com\/blog\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/people\/Threatcop\/100083109892339\/","https:\/\/x.com\/threatcop","https:\/\/www.linkedin.com\/company\/threatcop\/","https:\/\/www.instagram.com\/threatcop_official\/"]},{"@type":"Person","@id":"https:\/\/threatcop.com\/blog\/#\/schema\/person\/b726b18845470084a82f5fed6875910b","name":"Shikha Mishra","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2025\/08\/avatar_user_22_1756470936.png","url":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2025\/08\/avatar_user_22_1756470936.png","contentUrl":"https:\/\/threatcop.com\/blog\/wp-content\/uploads\/2025\/08\/avatar_user_22_1756470936.png","caption":"Shikha Mishra"},"description":"Shikha Mishra is responsible for driving the growth and adoption of TDMARC, a flagship product of Threatcop, across India, the Middle East, APAC, and the UK region. With her expertise, she helps organizations safeguard their domains so that no hacker can misuse them to send fraudulent emails, thereby protecting both their brand and reputation. She is passionate about enabling businesses to simplify the complexities of outbound email security through TDMARC\u2019s comprehensive solution, allowing them to stay focused on what matters most to their success.","sameAs":["https:\/\/threatcop.com\/","https:\/\/www.linkedin.com\/in\/shikha-mishra-9594771b5\/"]}]}},"_links":{"self":[{"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/posts\/15717","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/comments?post=15717"}],"version-history":[{"count":1,"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/posts\/15717\/revisions"}],"predecessor-version":[{"id":15731,"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/posts\/15717\/revisions\/15731"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/media\/15724"}],"wp:attachment":[{"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/media?parent=15717"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/categories?post=15717"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/threatcop.com\/blog\/wp-json\/wp\/v2\/tags?post=15717"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}