all-in-one privacy solution":["Proton Unlimited est une solution tout-en-un respectueuse de la vie privée"],"Black Friday":["Black Friday"],"No ads. Privacy by default.":["Aucune publicité, le respect de la vie privée comme règle absolue"],"People before profits":["Les individus passent avant les profits"],"Security through transparency":["Notre engagement de transparence"],"The best Proton Mail ${ BLACK_FRIDAY } deals":["Les meilleures offres ${ BLACK_FRIDAY } de Proton Mail"],"The world’s only community- supported email service":[" La seule messagerie au monde soutenue par la communauté"]},"specialoffer:limited":{"${ hours } hour":["${ hours } heure","${ hours } heures"],"${ hoursLeft }, ${ minutesLeft } and ${ secondsLeft } left":["Temps restant : ${ hoursLeft }, ${ minutesLeft }, ${ secondsLeft }"],"${ minutes } minute":["${ minutes } minute","${ minutes } minutes"],"${ seconds } second":["${ seconds } seconde","${ seconds } secondes"],"Limited time offer":["Offre à durée limitée"]},"specialoffer:listitem":{"Create multiple addresses":["Créez plusieurs adresses"],"Hide-my-email aliases":["Alias « hide-my-email »"],"Quickly unsubscribe from newsletters":["Désabonnez-vous rapidement des newsletters"],"Use your own domain name":["Utilisez votre propre nom de domaine"]},"specialoffer:logos":{"As featured in":["Ils en parlent"]},"specialoffer:metadescription":{"Get an encrypted email that protects your privacy":["Choisissez une messagerie électronique chiffrée qui protège votre vie privée"]},"specialoffer:metatitle":{"Proton Mail Black Friday Sale - Up to 40% off":["Offre Proton Mail Black Friday - Jusqu'à 40 % de réduction"]},"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.":["Obtenez jusqu'à 40 % de réduction sur les abonnements Proton Mail à l'occasion du Black Friday. Profitez d'offres exceptionnelles sur nos abonnements de messagerie électronique sécurisée et chiffrée de bout en bout."]},"specialoffer:newmetatitle":{"Proton Mail Black Friday sale | Up to 40% off secure email":["Offre Black Friday Proton Mail | Jusqu'à 40 % de réduction"]},"specialoffer:note":{"* Billed at ${ TOTAL_SUM } for the first year":["* Facturé ${ TOTAL_SUM } pour la première année"],"*Billed at ${ TOTAL_SUM } for the first 2 years":["*Facturé ${ TOTAL_SUM } pour les 2 premières années"],"30-day money-back guarantee":["Garantie satisfait ou remboursé pendant 30 jours"],"Billed at ${ TOTAL_SUM } for the first 2 years":["Facturé ${ TOTAL_SUM } pour les 2 premières années"],"Billed at ${ TOTAL_SUM } for the first year":["Facturé ${ TOTAL_SUM } pour la première année"],"You save ${ SAVE_SUM }":["Vous économisez ${ SAVE_SUM }"]},"specialoffer:off":{"${ PERCENT_OFF } off":["-${ PERCENT_OFF }"]},"specialoffer:testimonial":{"I love my ProtonMail":["J'adore mon ProtonMail"],"My favorite email service":["Ma messagerie électronique préférée"],"Thanks Proton for keeping us all safe in the complicated internet universe.":["Merci Proton de nous garder en sécurité dans l'univers complexe d'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":["Vous avez ce pour quoi vous payez. Avec les Big Tech, si vous ne payez rien, vous êtes utilisé. J'ai arrêté d'utiliser Gmail et je suis passée @ProtonMail"]},"specialoffer:time":{"Days":["Jours"],"Hours":["Heures"],"Min":["Min"]},"specialoffer:title":{"And much more":["Et aussi"],"Safe from trackers":["À l'abri des traqueurs"],"Stay organized":["Restez organisé(e)"],"Black Friday email deals":["Offres Black Friday pour la messagerie électronique"],"Don’t just take our word for it":["Ce qu'en disent nos utilisateurs"],"Make your inbox yours":["Appropriez-vous totalement votre boîte de réception"],"Our story":["Notre histoire"],"Transfer your data from Google in one click":["Transférez vos données depuis Google en un 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.":["Accédez aux contenus bloqués et naviguez en toute confidentialité. Comprend plus de ${ TOTAL_VPN_SERVERS } serveurs dans plus de ${ TOTAL_VPN_COUNTRIES } pays, la possibilité de connecter jusqu'à 10 appareils, l'accès aux services de streaming dans le monde entier, un bloqueur de logiciels malveillants et de publicités et bien plus encore."],"Easily share your calendar with your family, friends or colleagues, and view external calendars.":["Partagez facilement votre calendrier avec votre famille, vos amis ou collègues et consultez des calendriers externes."],"Includes support for 1 custom email domain, 10 email addresses, 10 hide-my-email aliases, calendar sharing, and more.":["Comprend la prise en charge de 1 domaine de messagerie personnalisé, de 10 adresses e-mail, de 10 alias « hide-my-email », du partage de calendriers et bien d'autres fonctionnalités."],"Includes support for 3 custom email domains, 15 email addresses, unlimited hide-my-email aliases, calendar sharing, and more.":["Comprend la prise en charge de 3 domaines de messagerie personnalisés, de 15 adresses e-mail, d'un nombre illimité d'alias « hide-my-email », du partage de calendriers et bien d'autres fonctionnalités."],"Manage up to 25 calendars, mobile apps, secured with end-to-end encryption, 1-click calendar import from Google, and more.":["Jusqu'à 25 calendriers, des applications mobiles, la sécurité avec le chiffrement de bout en bout, l'importation de calendrier en un clic depuis Google..."]},"Status Banner":{"At the moment we are experiencing issues with the Proton VPN service":["Nous rencontrons actuellement des problèmes avec le service Proton VPN."]},"Status banner":{"Learn more":["En savoir plus"],"Please note that at the moment we are experiencing issues with the ${ issues[0] } service.":["Nous rencontrons actuellement des problèmes avec le service ${ issues[0] }."],"We are experiencing issues with one or more services at the moment.":["Nous rencontrons actuellement des problèmes avec un ou plusieurs services."]},"steps":{"Step":["Étape"]},"suggestions":{"Suggestions":["Suggestions"]},"Support":{"Sub category":["Sous-catégorie","Sous-catégories"]},"Support article":{"${ readingTime } min":["${ readingTime } minute","${ readingTime } minutes"],"Category":["Catégorie","Catégories"],"Didn’t find what you were looking for?":["Vous ne trouvez pas ce que vous cherchez ?"],"General contact":["Contact - Général"],"Get help":["Obtenir de l'aide"],"Legal contact":["Contact - Juridique"],"Media contact":["Contact - Média"],"Partnerships contact":["Contact - Partenariats"],"Reading":["Lecture"]},"Support Form Platform option":{"VPN for Android TV":["VPN pour Android TV"],"VPN for Apple TV":["VPN pour Apple TV"],"VPN for Chromebook":["VPN pour Chromebook"]},"Support troubleshooting":{"App version":["Version de l'application"],"Browser":["Navigateur"],"Check if this helps":["Vérifiez si cela vous aide."],"Choose a product":["Choisir un produit"],"Did this solve your issue?":["Cela a-t-il résolu votre problème ?"],"Faster assistance is just a few clicks away":["Quelques clics suffisent pour obtenir une assistance plus rapide"],"How can we help?":["Comment pouvons-nous vous aider ?"],"No, contact support":["Non, contacter le support"],"Please fill out one field after another":["Veuillez remplir les champs l'un après l'autre"],"Please make your selections":["Veuillez faire vos sélections"],"Proton account":["Compte Proton"],"Proton for Business":["Proton for Business"],"Thank you for your feedback":["Nous vous remercions pour votre commentaire."],"What can we help with?":["En quoi pouvons-nous vous aider ?"],"Yes":["Oui"]},"support_modal_search_query":{"Search query":["Recherche"]},"support_search_button":{"Search":["Rechercher"]},"support_search_i_am_looking_for":{"I'm looking for":["Je recherche des informations sur..."]},"SupportForm":{"For a faster resolution, please report the issue from the Bridge app: Help > Report a problem.":["Pour que le problème soit résolu plus rapidement, vous pouvez le signaler à partir de l'application Bridge : Aide > Signaler un bug."],"Information":["Informations"]},"SupportForm:option":{"Account Security":["Sécurité du compte"],"Contacts":["Contacts"],"Custom email domain":["Domaine de messagerie personnalisé"],"Email delivery and Spam":["Distribution des messages et indésirables/spam"],"Encryption":["Chiffrement"],"Login and password":["Identifiant et mot de passe"],"Merge aliases and accounts":["Fusion des alias et des comptes"],"Migrate to Proton":["Migration vers Proton"],"Notifications":["Notifications"],"Other":["Autre"],"Plans and billing":["Abonnements et facturation"],"Proton for Business":["Proton for Business"],"Sign up":["Inscription"],"Storage":["Espace de stockage"],"Users, addresses, and identities":["Utilisateurs, adresses et identités"]},"SupportForm:optionIntro":{"Select a topic":["Choisissez un sujet"]},"Testimonial":{"Awards":["Récompenses"],"Customers":["Clients"],"Featured":["Ils en parlent"],"Go to testimonial source":["Accéder aux commentaires"],"Open source of award":["Voir l'information originale concernant ce prix"],"Open source of quote":["Voir l'information originale concernant cette citation"],"Reviews":["Avis"],"Videos":["Vidéos"],"Watch on TikTok":["Regarder sur TikTok"],"Watch on YouTube":["Regarder sur YouTube"]},"TestimonialCategory":{"Awards":["Récompenses"],"Customers":["Clients"],"Featured":["Ils en parlent"],"Media":["Média"],"Reviews":["Avis"],"Videos":["Des vidéos"]},"Text":{"If you need help, check out our ${ supportLink }.":["Si vous avez besoin d'aide, consultez notre ${ supportLink }."],"The page you’re looking for might have been removed, or it could be an\nold link.":["La page recherchée a peut-être été retirée ou le lien utilisé n'est plus valide."],"Your question may already have an answer in our knowledge base:":["La réponse à votre question se trouve peut-être déjà dans notre base de connaissances :"]},"Title":{"On this page":["Sur cette page"],"Page not found":["Page introuvable"],"Related articles":["Articles similaires"],"Share ${ thisPage }":["Partagez ${ thisPage }"],"Switch to Proton Pass - Contact us":["Passez à Proton Pass - Contactez-nous"],"Thank you!":["Merci !"],"this page":["cette page"]},"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.":["Accédez aux contenus bloqués et naviguez en toute confidentialité. Comprend plus de ${ TOTAL_VPN_SERVERS } serveurs dans plus de ${ TOTAL_VPN_COUNTRIES } pays, la vitesse VPN la plus élevée, ${ TOTAL_VPN_CONNECTIONS } connexions VPN, l'accès aux services de streaming dans le monde entier, un bloqueur de logiciels malveillants et de publicités et bien plus encore."]},"vpn_servers":{"Get Proton VPN Plus":["Je choisis Proton VPN Plus"]},"wallet_signup_2024:Action":{"Get Proton Wallet":["Obtenir Proton Wallet"]},"wallet_signup_2024:Homepage hero product link title":{"Wallet":["Wallet"]},"wallet_signup_2024:Homepage product navigation bar":{"Wallet":["Wallet"]},"wallet_signup_2024:menu item":{"Bitcoin guide":["Guide de Bitcoin"],"Proton Wallet news":["Actualités Proton Wallet"],"Proton Wallet support":["Support Proton Wallet"]},"wallet_signup_2024:Pricing":{"Includes everything in Proton Unlimited and":["Comprend tout ce qui est inclus dans Proton Unlimited et"],"Limited availability":["Disponibilité limitée"],"The easiest way to securely own, send, and receive Bitcoin":["Le moyen le plus simple et sécurisé pour détenir et échanger des bitcoins"]},"wallet_signup_2024:ProductRange":{"Discover Proton Wallet":["Découvrez Proton Wallet"],"Store and transact Bitcoin privately with an encrypted self-custody wallet.":["Conservez et échangez des bitcoins en toute sécurité grâce à notre portefeuille chiffré en auto-gestion."]},"wallet_signup_2024:wallet bitcoin":{"Learn about Bitcoin, the Internet's value network.":["Découvrez le monde du Bitcoin, le réseau de valeur sur Internet."]},"wallet_signup_2024:wallet overview":{"Ensure you're always in control of your Bitcoin.":["Restez maître de vos bitcoins en toutes circonstances."]},"wallet_signup_2024:wallet security":{"The encrypted, open-source wallet that puts you in control.":["Contrôlez vos bitcoins de A à Z avec notre portefeuille chiffré open source."]}}},"base":"blog","cdn":{"enabledForAssets":true,"enabledForImages":true,"url":"https://pmecdn.protonweb.com/"},"unleashApi":"https://account.proton.me/api"};
window.frameworkContext = frameworkContext;
const context = frameworkContext.base === '' ? '' : `${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(nouvelle fenêtre), 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 five parts:
Infostealer delivery
Data collection
Data exfiltration
Data distribution
Further criminal activity
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.
Data distribution
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.
Further 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.
Thousands of businesses of all sizes were impacted by cybercrime in 2024. Here
are the top cybersecurity threats we expect companies to face in 2025—and how
Proton Pass can protect your business.