all-in-one privacy solution":["Proton Unlimited es una solución de privacidad todo en uno"],"Black Friday":["Black Friday"],"No ads. Privacy by default.":["Sin anuncios. Privacidad por defecto."],"People before profits":["Primero las personas, luego los beneficios"],"Security through transparency":["Seguridad con transparencia"],"The best Proton Mail ${ BLACK_FRIDAY } deals":["Las mejores ofertas de Proton Mail en el ${ BLACK_FRIDAY }"],"The world’s only community- supported email service":["El único servicio de correo electrónico del mundo financiado por la comunidad"]},"specialoffer:limited":{"${ hours } hour":["${ hours } hora","${ hours } horas"],"${ hoursLeft }, ${ minutesLeft } and ${ secondsLeft } left":["Tiempo restante: ${ hoursLeft }, ${ minutesLeft } y ${ secondsLeft }"],"${ minutes } minute":["${ minutes } minuto","${ minutes } minutos"],"${ seconds } second":["${ seconds } segundo","${ seconds } segundos"],"Limited time offer":["Oferta por tiempo limitado"]},"specialoffer:listitem":{"Create multiple addresses":["Cree múltiples direcciones"],"Hide-my-email aliases":["Seudónimos de hide-my-email"],"Quickly unsubscribe from newsletters":["Cancele suscripciones a boletines rápidamente"],"Use your own domain name":["Use su propio dominio"]},"specialoffer:logos":{"As featured in":["Tal como aparece en"]},"specialoffer:metadescription":{"Get an encrypted email that protects your privacy":["Obtenga un correo electrónico cifrado que protege su privacidad"]},"specialoffer:metatitle":{"Proton Mail Black Friday Sale - Up to 40% off":["Oferta de Black Friday de Proton Mail: hasta un 40% de descuento"]},"specialoffer:newmetadescription":{"Get up to 40% off Proton Mail subscriptions this Black Friday. Find great deals on our secure end-to-end encrypted email plans.":["Aproveche las rebajas de Black Friday y obtenga suscripciones de Proton Mail con hasta un 40 % de descuento. Encontrará las mejores ofertas en planes de correo electrónico seguro cifrado de extremo a extremo."]},"specialoffer:newmetatitle":{"Proton Mail Black Friday sale | Up to 40% off secure email":["Rebajas de Black Friday en Proton Mail | Hasta un 40 % de descuento en correo electrónico seguro"]},"specialoffer:note":{"* Billed at ${ TOTAL_SUM } for the first year":["*Con un costo de ${ TOTAL_SUM } durante el primer año"],"*Billed at ${ TOTAL_SUM } for the first 2 years":["*Con un costo de ${ TOTAL_SUM } durante los primeros 2 años"],"30-day money-back guarantee":["Garantía de devolución de dinero de 30 días"],"Billed at ${ TOTAL_SUM } for the first 2 years":["Con un costo de ${ TOTAL_SUM } durante los primeros 2 años"],"Billed at ${ TOTAL_SUM } for the first year":["Con un costo de ${ TOTAL_SUM } durante el primer año"],"You save ${ SAVE_SUM }":["Ahorre ${ SAVE_SUM }"]},"specialoffer:off":{"${ PERCENT_OFF } off":["-${ PERCENT_OFF }"]},"specialoffer:testimonial":{"I love my ProtonMail":["Amo mi Proton Mail"],"My favorite email service":["Mi servicio de correo electrónico favorito"],"Thanks Proton for keeping us all safe in the complicated internet universe.":["Gracias Proton por mantenernos a salvo en el complicado universo de Internet."],"You get what you pay for. In the case of big tech, if you pay nothing, you get used. I quit using Gmail and switched to @ProtonMail":["Obtiene aquello por lo que paga. En el caso de la gran tecnología, cuando uno no paga nada, se acostumbra. Dejé de usar Gmail y cambié a @ProtonMail"]},"specialoffer:time":{"Days":["Días"],"Hours":["Horas"],"Min":["min"]},"specialoffer:title":{"And much more":["Y mucho más"],"Safe from trackers":["A salvo de rastreadores"],"Stay organized":["Mantenga todo en orden"],"Black Friday email deals":["Ofertas en correo electrónico del Black Friday"],"Don’t just take our word for it":["No confíe solo en nuestra palabra"],"Make your inbox yours":["Tome posesión de su bandeja de entrada"],"Our story":["Nuestra historia"],"Transfer your data from Google in one click":["Transfiera sus datos de Google con un solo clic"]},"specialoffer:tooltip":{"Access blocked content and browse privately. Includes ${ TOTAL_VPN_SERVERS }+ servers in ${ TOTAL_VPN_COUNTRIES }+ countries, connect up to 10 devices, access worldwide streaming services, malware and ad-blocker, and more.":["Acceda a contenidos bloqueados y navegue de forma privada. Incluye más de ${ TOTAL_VPN_SERVERS } servidores en más de ${ TOTAL_VPN_COUNTRIES } países, se conecta con hasta 10 dispositivos, accede a servicios de transmisión de todo el mundo, bloquea malware y publicidad y mucho más."],"Easily share your calendar with your family, friends or colleagues, and view external calendars.":["Comparta su calendario con familiares, amigos y compañeros fácilmente y consulte calendarios externos."],"Includes support for 1 custom email domain, 10 email addresses, 10 hide-my-email aliases, calendar sharing, and more.":["Incluye compatibilidad con 1 dominio de correo electrónico personalizado, 10 direcciones de correo electrónico, 10 seudónimos de hide-my-email, posibilidad de compartir calendario, etc."],"Includes support for 3 custom email domains, 15 email addresses, unlimited hide-my-email aliases, calendar sharing, and more.":["Incluye compatibilidad con 3 dominios de correo electrónico personalizado, 15 direcciones de correo electrónico, seudónimos ilimitados de hide-my-email, posibilidad de compartir calendario, etc."],"Manage up to 25 calendars, mobile apps, secured with end-to-end encryption, 1-click calendar import from Google, and more.":["Administre hasta 25 calendarios, apps móviles, protegido con cifrado de extremo a extremo, importación de calendario con 1 clic desde Google y más."]},"Status banner":{"Learn more":["Más información"],"Please note that at the moment we are experiencing issues with the ${ issues[0] } service.":["Tenga en cuenta que, en este momento, estamos experimentando problemas con el servicio ${ issues[0] }."],"We are experiencing issues with one or more services at the moment.":["En este momento, tenemos problemas con uno o más servicios."]},"Status Banner":{"At the moment we are experiencing issues with the Proton VPN service":["En este momento, tenemos problemas con el servicio Proton VPN."],"Learn more":["Más información"]},"steps":{"Step":["Paso"]},"suggestions":{"Suggestions":["Sugerencias"]},"Support":{"Sub category":["Subacategoria","Subcategorías"]},"Support article":{"${ readingTime } min":["${ readingTime } minuto","${ readingTime } minutos"],"Category":["Categoría","Categorías"],"Didn’t find what you were looking for?":["¿No encontró lo que buscaba?"],"General contact":["Contacto general"],"Get help":["Obtener ayuda"],"Legal contact":["Contacto legal"],"Media contact":["Contacto para medios"],"Partnerships contact":["Contacto para colaboradores"],"Reading":["Lectura"]},"Support Form Platform option":{"VPN for Android TV":["VPN para Android TV"],"VPN for Apple TV":["VPN para Apple TV"],"VPN for Chromebook":["VPN para Chromebook"]},"Support troubleshooting":{"App version":["Versión de la app"],"Browser":["Navegador"],"Check if this helps":["Compruebe si le sirve"],"Choose a product":["Elija un producto"],"Did this solve your issue?":["¿Le ha resultado útil para resolver el problema?"],"Faster assistance is just a few clicks away":["Solo le separan unos clics de una asistencia más rápida"],"How can we help?":["¿Cómo podemos ayudarle?"],"No, contact support":["No, contactar a soporte"],"Please fill out one field after another":["Complete un campo después de otro"],"Please make your selections":["Realice sus selecciones"],"Proton account":["Cuenta de Proton"],"Proton for Business":["Proton for Business"],"Thank you for your feedback":["Gracias por sus comentarios"],"What can we help with?":["¿En qué podemos ayudarle?"],"Yes":["Sí"]},"support_modal_search_query":{"Search query":["Consulta"]},"support_search_button":{"Search":["Buscar"]},"support_search_i_am_looking_for":{"I'm looking for":["Busco"]},"SupportForm":{"For a faster resolution, please report the issue from the Bridge app: Help > Report a problem.":["Para una resolución más rápida, reporte el problema desde la app Bridge: Ayuda > Reportar un problema."],"Information":["Información"]},"SupportForm:option":{"Account Security":["Seguridad de la cuenta"],"Contacts":["Contactos"],"Custom email domain":["Dominio de correo electrónico personalizado"],"Email delivery and Spam":["Entrega de correo electrónico y spam"],"Encryption":["Cifrado"],"Login and password":["Inicio de sesión y contraseña"],"Merge aliases and accounts":["Combinar alias y cuentas"],"Migrate to Proton":["Migrar a Proton"],"Notifications":["Notificaciones"],"Other":["Otros"],"Plans and billing":["Planes y facturación"],"Proton for Business":["Proton for Business"],"Sign up":["Regístrese"],"Storage":["Almacenamiento"],"Users, addresses, and identities":["Usuarios, direcciones e identidades"]},"SupportForm:optionIntro":{"Select a topic":["Seleccione un tema"]},"Testimonial":{"Awards":["Premios"],"Customers":["Clientes"],"Featured":["Destacados"],"Go to testimonial source":["Ir a la fuente testimonial"],"Open source of award":["Abrir fuente del premio"],"Open source of quote":["Abrir fuente de la cita"],"Reviews":["Reseñas"],"Videos":["Videos"],"Watch on TikTok":["Ver en TikTok"],"Watch on YouTube":["Ver en YouTube"]},"TestimonialCategory":{"Awards":["Premios"],"Customers":["Clientes"],"Featured":["Destacados"],"Media":["Medios"],"Reviews":["Reseñas"],"Videos":["Videos"]},"Text":{"If you need help, check out our ${ supportLink }.":["Si necesita ayuda, consulte nuestra ${ supportLink }."],"The page you’re looking for might have been removed, or it could be an\nold link.":["Es posible que la página que busca haya sido eliminada o que sea un\nenlace antiguo."],"Your question may already have an answer in our knowledge base:":["Puede que haya respuesta a su pregunta en nuestra base de conocimientos:"]},"Title":{"On this page":["En esta página"],"Related articles":["Artículos relacionados"],"Share ${ thisPage }":["Compartir ${ thisPage }"],"Switch to Proton Pass - Contact us":["Cambie a Proton Pass - Contáctenos"],"Thank you!":["¡Gracias!"],"this page":["esta página"]},"tooltip_vpn":{"Access blocked content and browse privately. Includes ${ TOTAL_VPN_SERVERS }+ servers in ${ TOTAL_VPN_COUNTRIES }+ countries, highest VPN speed, ${ TOTAL_VPN_CONNECTIONS } VPN connections, worldwide streaming services, malware and ad-blocker, and more.":["Acceda a contenidos bloqueados y navegue de forma privada. Incluye más de ${ TOTAL_VPN_SERVERS } servidores en más de ${ TOTAL_VPN_COUNTRIES } países, la mayor velocidad VPN, ${ TOTAL_VPN_CONNECTIONS } conexiones VPN, servicios de transmisión en todo el mundo, bloqueador de malware y publicidad y mucho más."]},"vpn_servers":{"Get Proton VPN Plus":["Obtener Proton VPN Plus"]},"wallet_signup_2024:Action":{"Get Proton Wallet":["Obtener Proton Wallet"]},"wallet_signup_2024:Homepage hero product link title":{"Wallet":["Wallet"]},"wallet_signup_2024:Homepage product navigation bar":{"Wallet":["Wallet"]},"wallet_signup_2024:menu item":{"Bitcoin guide":["Guía sobre Bitcoin"],"Proton Wallet news":["Novedades sobre Proton Wallet"],"Proton Wallet support":["Soporte para Proton Wallet"]},"wallet_signup_2024:Pricing":{"Includes everything in Proton Unlimited and":["Incluye todas las funciones en Proton Unlimited y"],"Limited availability":["Disponibilidad limitada"],"The easiest way to securely own, send, and receive Bitcoin":["La forma más fácil de retener, enviar y recibir Bitcoin con seguridad"]},"wallet_signup_2024:ProductRange":{"Discover Proton Wallet":["Descubra Proton Wallet"],"Store and transact Bitcoin privately with an encrypted self-custody wallet.":["Almacene Bitcoin y negocie de forma privada con una cartera de autocustodia cifrada."]},"wallet_signup_2024:wallet bitcoin":{"Learn about Bitcoin, the Internet's value network.":["Infórmese sobre Bitcoin, la red de valor de internet."]},"wallet_signup_2024:wallet overview":{"Ensure you're always in control of your Bitcoin.":["Asegúrese de tener siempre el control de su Bitcoin."]},"wallet_signup_2024:wallet security":{"The encrypted, open-source wallet that puts you in control.":["La cartera cifrada de código abierto que le permite controlarlo todo."]}}},"base":"blog","cdn":{"enabledForAssets":true,"enabledForImages":true,"url":"https://pmecdn.protonweb.com/"},"unleashApi":"https://account.proton.me/api"};
window.frameworkContext = frameworkContext;
const context = frameworkContext.base === '' ? '' : `${frameworkContext.base}/`;
window.__toAssetUrl = (filename) => {
if (frameworkContext.cdn !== undefined && frameworkContext.cdn.enabledForAssets === true) {
return `${frameworkContext.cdn.url}${context}${filename}`;
} else {
return `/${context}${filename}`;
}
};
})();
Infostealers: What they are, how they work, and how to protect yourself | Proton
In an ever-evolving cyber threat landscape, infostealers — malicious programs designed to gather sensitive information from infected systems and send that information back to an attacker — have emerged as a growing threat to individuals and organizations alike.
According to a report released this year by Constella Intelligence(nueva ventana), more than 500 million devices in 2023 were found to be infected with nearly 2 billion infostealer records, including usernames, passwords, credit card numbers, Social Security numbers, and other sensitive information.
While the rise of infostealers is notable, they are not new. What has changed, however, is the business model and sophistication of the infostealer ecosystem. Previously, malicious groups needed specialized expertise to develop malware. Today, they can simply use malware-as-a-service (MaaS) for a $120 monthly payment. This shift has opened new revenue streams for existing malware developers and a potential doorway for criminals with no particular technical skills.
This blog post will delve into what infostealers are, how they operate, and where the data they collect goes. We will also explore the reliability of infostealer data and how you can protect yourself.
If you are already using Proton Mail and have Proton Sentinel enabled, you automatically have enhanced protection from infostealers, as Proton Sentinel detects logins from malicious actors, even if they have already stolen your credentials. Dark Web Monitoring in Proton Mail and Proton Pass also warns you if it detects that any of your credentials have been leaked onto the dark web.
What are infostealers?
Infostealers are a type of malware designed to steal from a compromised system information including but not limited to:
Login credentials (usernames/email addresses and passwords)
Financial information (credit card numbers, bank account details)
Personal data (Social Security numbers, addresses, phone numbers)
Browser data (bookmarks, history, cookies)
Emails and chat logs
Images and documents
Crypto wallets
Screenshots (some infostealers take periodic screenshots and send them back to the attacker)
How do infostealers work?
Infostealers are often used in conjunction with other types of malware to create a more comprehensive attack.
They can be delivered through various means, including phishing emails, malicious websites, and infected software downloads. We can break down their operations into three parts:
Infostealer delivery
Data collection
Data exfiltration
Infostealer delivery
The first step in an infostealer attack is the infection of the target system. This can occur through:
Phishing emails: Emails containing malicious attachments or links that, when opened, download and install the infostealer.
Malicious websites: Visiting compromised or malicious websites that exploit vulnerabilities in the user’s browser to install the infostealer.
Malvertising: Using online advertising to spread malware, often by injecting malicious or malware-laden advertisements into legitimate websites — or even by compromising the social media accounts of companies and using this to create malicious ads.
Infected software: Downloading and installing software from untrusted sources that contains the infostealer. Typically, an attacker will put up “free” versions of popular software hoping that people will download them, which they often do.
Data collection
Once installed, the infostealer begins to collect data from the infected system. This process can involve:
Keyloggers: Almost all infostealers have a key logger, which provides attackers with every keystroke a user makes. Attackers can later sift through this data to extract passwords, credit card numbers, and other sensitive personal information.
Form grabbers: This technique intercepts data submitted through web forms before it is encrypted. It is particularly effective for stealing login credentials, payment details, and other information entered on websites.
Clipboard hijackers: Infostealers can monitor and alter the clipboard content on an infected device. When a user copies sensitive data like account numbers or passwords, the malware can replace or steal this information.
Remote access: Amore sophisticated type of malware, also commonly referred to as RATs (remote access trojans), this type of malware gives attackers remote access to a user’s machine. Once inside your machine, an attacker has access to everything they need. Famous examples include Agent Tesla, LokiBot, and TrickBot.
Screen captures: By taking screenshots at crucial moments, such as when a user is entering credentials or viewing personal information, this method bypasses the limitations of text-based data extraction. It captures any data displayed on the screen.
Browser session hijacking: This method — present in stealers such as RacoonStealer — involves stealing cookies and session tokens from a browser’s memory. Cybercriminals can use this to impersonate the user’s online session, gaining unauthorized access to accounts without needing a username and password.
File harvesting: The malware searches through files and emails on the computer to gather information, which can include login credentials, images, sensitive documents, communications, and more.
Crypto wallet harvesters: Some Infostealer malware, such as LokiBot, can search for common crypto-wallet software and attempt to steal private keys. Once in the attacker’s possession, these keys can be used to transfer the victim’s cryptocurrency to attacker-controlled accounts.
Data exfiltration
The collected data is then transmitted to the attacker’s server. This can be done through:
HTTP/HTTPS requests: Sending the data to a web server controlled by the attacker — or via APIs to reputable file-sharing sites.
FTP transfers: Uploading the data to an FTP server.
Email: Sending the data via email to the attacker.
Where does infostealer data go?
The data collected by infostealers is often sold or traded in one of two places: a centralized marketplace or a decentralized marketplace.
Centralized marketplaces, such as the now defunct Genesis marketplace, provide a one-stop shop for infostealer data.
Decentralized options also exist, such as Telegram bots like the one pictured below. Here, criminals request what they need (credentials used on Lufthansa, for example), and the bot will respond with how many records exist. The attacker can then request those records, pay a price directly, and receive the logs.
A path for criminal activity
Cybercriminals can then use this stolen data for various malicious purposes, including:
Identity theft: Using personal information to impersonate the victim.
Financial fraud: Using financial information to make unauthorized transactions.
Phishing attacks: Using the stolen data to craft more convincing phishing emails.
Ransomware attacks: Using the stolen data to extort the victim.
Sextortion/blackmail: Gaining access to the user’s files can result in threats to expose their data.
Is infostealer data reliable?
While infostealers can collect a vast amount of data, the reliability of this data is not always guaranteed.
User mistakes
Users can make mistakes when entering data, which can lead to the inclusion of incorrect or irrelevant information. For example, a user might accidentally type a friend’s email address instead of their own when signing up for a service. This mistake can result in the infostealer collecting and transmitting the friend’s email address, potentially leading to the friend being targeted by the attacker instead.
Cybercriminals who test stolen passwords may have their own computers infected with infostealer malware.
When these compromised criminals test lists of stolen credentials, the infostealer captures this activity.
Much of this testing involves old, invalid credentials from previous data breaches found on dark web forums.
As a result, when someone sees their old password appearing in malware logs, they might incorrectly assume their computer is currently infected.
In reality, their information may have come from an old data breach where just one password was compromised, rather than from active malware on their system.
In short, it may just be a criminal testing old stolen passwords on their malware-infected computer that creates logs that make it look like many people have malware, when actually those people had their passwords leaked in the past.
Corrupted data
Infostealers can also collect data that is incomplete or corrupted.
For example, a keylogger might not capture all keystrokes, or a file scanner might miss certain types of files. This can lead to gaps in the collected data, making it less useful for the attacker.
How to protect yourself from infostealers
Here are some ways you can protect yourself right now.
Use a virus scanner to ensure your system is protected from malware.
Be careful of phishing, using tools like NetShield, which is built into ProtonVPN, to protect yourself from known malicious links; only download attachments from known contacts (and even then be vigilant).
Enable Dark Web Monitoring on your Proton account to detect and respond to threats quickly.
Monitor account accesses carefully and set up activity alerts with your bank.
A growing threat
Infostealers are a significant threat in the world of cybersecurity, capable of collecting a wide range of sensitive information from infected systems. Understanding how they work and the distribution of the data they collect is crucial for protecting against these threats.
However, it’s also important to recognize that infostealer data is not always reliable due to user mistakes, accidental infections, and data integrity issues. By staying informed and taking proactive security measures, individuals and organizations can better protect themselves from the dangers of infostealers.