E-mail Spoofing : Comment l’éviter et protéger votre entreprise

E-mail Spoofing : Comment l’éviter et protéger votre entreprise

​
​
Vous est-il déjà arrivé de recevoir un e-mail qui semblait légitime — avec le bon logo, un ton familier — mais qui vous a tout de même paru suspect ? Pire encore, un de vos clients vous a-t-il déjà contacté après avoir reçu un e-mail douteux qui semblait provenir de votre entreprise ?
C’est ça, le spoofing d’e-mail.
Le spoofing d’e-mail est une technique utilisée par des cybercriminels pour falsifier l’adresse de l’expéditeur afin de faire croire que le message provient d’une source fiable — souvent une entreprise connue. Leur objectif ? Tromper le destinataire pour l’amener à cliquer sur un lien malveillant ou à divulguer des informations sensibles.
Dans cet article, nous allons vous expliquer comment fonctionne le spoofing d’e-mail, les risques qu’il représente et, surtout, les actions que vous pouvez mettre en place pour protéger votre entreprise et vos clients.

À quoi ressemble un e-mail spoof ?

Voici les éléments clés à surveiller pour identifier un e-mail spoofé :
  • Spoofing du nom d’affichage : un e-mail où le nom d’affichage est identique ou très proche de celui d’un employé réel de l’entreprise. Cela crée un faux sentiment de légitimité.
  • Spoofing du domaine : l’expéditeur falsifie non seulement le nom d’affichage, mais aussi le nom de domaine de l’entreprise. L’adresse e-mail semble alors provenir du domaine officiel, rendant la fraude plus difficile à détecter.
  • Adresse de l’expéditeur suspecte : c’est souvent un indice révélateur. Même si le nom d’affichage peut sembler familier, le domaine qui suit le symbole “@” est souvent différent ou étrange. Cela trahit généralement une tentative de spoofing.
  • Un ton pressant ou menaçant : les cybercriminels utilisent souvent un langage alarmant pour pousser le destinataire à agir rapidement, sans prendre le temps de réfléchir. Cela peut inclure des menaces ou une fausse urgence.
  • Promesses de gains ou de cadeaux : ces e-mails prétendent souvent que vous avez gagné un prix ou une récompense. Cela pousse les victimes à fournir des informations personnelles ou à cliquer sur des liens ou pièces jointes malveillants pouvant infecter leurs appareils.
  • Incohérences visuelles : certains e-mails spoofés présentent des logos obsolètes, des fautes de mise en page ou un format différent des communications habituelles de l’entreprise. Bien que les fraudeurs deviennent de plus en plus habiles à imiter le style visuel, certaines tentatives restent faciles à repérer.

Stopper le spoofing d’e-mail : les bonnes pratiques à connaître

Le spoofing d’e-mail peut être limité, voire empêché, en configurant plusieurs mécanismes d’authentification comme SPF, DKIM et DMARC. Chacun joue un rôle distinct dans la vérification des messages, mais c’est leur mise en œuvre conjointe qui permet de protéger efficacement votre domaine contre les tentatives de spoofing.

Sender Policy Framework (SPF)

SPF est un protocole d’authentification des e-mails conçu pour vérifier l’identité de l’expéditeur.
Pour mettre en place SPF, vous devez déclarer les adresses IP ou serveurs de messagerie autorisés à envoyer des e-mails en votre nom. Lorsqu’un e-mail est reçu, le serveur de réception interroge le serveur DNS du domaine pour vérifier si l’adresse IP de l’expéditeur figure bien parmi celles autorisées. Si ce n’est pas le cas, le message peut être marqué comme suspect ou bloqué.
L’e-mail n’est délivré dans la boîte de réception du destinataire que s’il provient d’une adresse IP autorisée et s’il réussit la validation SPF. En configurant correctement les enregistrements SPF, vous pouvez améliorer la délivrabilité de vos messages, réduire les risques de spam et prévenir l’usurpation d’adresse e-mail.


DomainKeys Identified Mail (DKIM)

DKIM est une signature numérique ajoutée à chaque e-mail que vous envoyez. Elle fonctionne en complément des enregistrements SPF.
En plus de vérifier l’authenticité de l’expéditeur, DKIM permet de s’assurer que le contenu du message n’a pas été altéré ou modifié pendant son acheminement. C’est un moyen efficace de garantir l’intégrité des e-mails et de renforcer la confiance des destinataires.
Pour configurer DKIM, il faut publier une clé publique dans les enregistrements DNS de votre domaine. Lorsqu’un e-mail est envoyé, votre serveur génère une empreinte numérique du message (incluant le contenu et les titres) et la signe à l’aide d’une clé privée, qui reste confidentielle.
Lors de la réception, le serveur du destinataire utilise la clé publique pour vérifier si cette signature est bien authentique. Si l’empreinte correspond, cela signifie que le message n’a pas été altéré pendant son envoi.
Cette méthode garantit l’intégrité de vos e-mails et empêche les attaquants de se faire passer pour vous, puisqu’ils ne possèdent pas la clé privée nécessaire pour signer les messages.

DMARC (Domain-based Message Authentication, Reporting and Conformance)

DMARC est une méthode d’authentification avancée conçue pour prévenir le spoofing e-mail. Elle repose sur les protocoles SPF et DKIM, et permet de définir une politique claire à appliquer lorsqu’un message échoue à ces vérifications.
Concrètement, DMARC vous permet de publier une politique dans votre DNS indiquant aux serveurs de messagerie des destinataires quoi faire lorsqu’un e-mail ne passe pas les contrôles SPF ou DKIM. Trois actions sont possibles :
Action 1 : Aucune action
Aucune mesure n’est prise, même si le message échoue aux vérifications SPF ou DKIM.
L’e-mail est quand même transmis dans la boîte de réception du destinataire.
Action 2 : Quarantine
L’e-mail est livré, mais redirigé vers le dossier des spams ou courrier indésirable, car il n’a pas passé les contrôles SPF/DKIM.
Action 3 : Rejeter
Si cette politique est choisie, tout e-mail qui échoue aux vérifications SPF ou DKIM est simplement rejeté. Il ne sera jamais livré au destinataire.


Comment Zoho Campaigns vous aide à prévenir le spoofing d’identité par email et à protéger votre domaine

Zoho Campagins permet à chaque utilisateur de configurer facilement les enregistrements SPF et DKIM afin d’authentifier son domaine.
Si un email réussit les vérifications SPF et DKIM, la politique DMARC ne s’applique pas. En revanche, si l’une de ces vérifications échoue, le serveur de réception consulte alors la politique DMARC du domaine pour déterminer comment traiter le message. Il est important de noter qu’une politique DMARC ne peut être activée qu’après la mise en place des enregistrements SPF et DKIM, sans quoi la validation DMARC échouera.
Une fois l’authentification SPF et DKIM configurée pour votre domaine, vous pouvez définir la politique DMARC dans les enregistrements DNS de votre domaine. Vous pouvez en apprendre davantage sur la configuration des enregistrements DMARC ici.
Configurer SPF et DKIM permet non seulement de lutter contre spoofing e-mail, mais aussi d’améliorer la délivrabilité de vos messages. En plus de SPF et DKIM, Zoho Campaigns propose également plusieurs fonctionnalités axées sur la délivrabilité, afin d'assurer que vos emails atteignent toujours la boîte de réception.
E-mail spoofing évolue constamment, et rester passif face à cette menace peut entraîner des pertes financières ou nuire à la réputation de votre entreprise.
En mettant en place de manière proactive des protocoles d’authentification email tels que SPF, DKIM et DMARC, les entreprises peuvent réduire considérablement les risques liés à l’usurpation d’identité par email.

L'équipe Zoho France

    • Sticky Posts

    • Collaboration sans faille avec Zoho One

      Bonjour à tous, Dans cet article nous allons voir comment Zoho One permet une collaboration à différents niveaux .       La façon dont nous travaillons évolue. À mesure que les entreprises se mondialisent, la plupart des activités sont menées en équipe.

    • Recent Topics

    • Error occured. please try again!!!

      I created a new list. Added two new contact's email addresses. I try to EDIT either one of them to add their first name, last name and phone number. Whatever I try to edit and update, I get the error message  Error occured. please try again!!! And it doesn't update any of their info. I tried just editing first and last name. Still get the error. No matter what I try to update, I get the error. I tried creating a new list, and adding just one email address and then edit it and also get the error.

    • "Send email as" not work

      Hi team, I currently use ZOHO MAIL services on the MAKE platform (formerly INTEGROMAT). In MAKE I entered my ZOHO MAIL credentials but the problem is that when the emails are sent from the automation in MAKE, the emails do not come in with the name set

    • *UPDATE: ISSUE RESOLVED, SEE HOW FOR HELP* Issue imbedding Youtube Videos

      **UPDATE: RESOLVED** For anyone that is having a similar issue, try this workaround before attempting to have the Zoho techs fix it. I have been in communication with them for weeks about this and they can't seem to fix the issue. Thinking it may have just been my computer or my browser, I tried two different computers on two different networks, each running different versions of Windows, and tried it on Chrome, Firefox and IE; nothing worked. So, needless to say, it's an issue with Zoho somewhere.

    • Backorder For Composite Items

      Hello If i released SO for composite item and use backorder feature of zoho inventory then it should backorder child item items of composite and not composite item.This is basic of backordering.I conveyed this to zoho call center but no solution yet.

    • Paid Support

      We are in the process of creating tiers for our support offerings. There will be three tiers of support available - 2 paid and 1 free. The paid tiers will be purchased in allotted hours. I need to figure out how to a) work in the out of the box SLA, Contracts

    • Automatically CC supervisor

      Hello,  in our organization agents are replying to tickets and they are required to CC their supervisor on all emails to and from customers.  is there a way to have an email address automatically populate in the CC field when reply to a ticket?  tha

    • Zoho One - White Label

      Releasing a white-label feature for Zoho One, or any software or service, can offer several advantages and benefits for both the company providing the software (Zoho in this case) and its users. Here are some key reasons for releasing a white-label feature

    • Are this Features included in the Road Map

      1. Sync between description/short description in Zoho Books/Inventory and Zoho Commerce: I am unsure how it works now. I belive the description is not pulled. 2. Pick Up: This feature is great. It is added on Zoho Commerce but not on Books/Inventory which

    • Reconciliation - Show Transactions After End Date

      I did a quick search, and I've only seen this brought up indirectly. In the reconciliation interface, transactions dated up to a week after the end date should be available for being reconciled. The use case is pretty simple... many times, transactions

    • Auto populate email field in zoho form

      Hi,  Is there a way the email field in zoho forms can be auto populated based on the name selected from a drop down list?

    • Option to accept and pay for estimate from Public Estimate link?

      Is there any way that our customers can get the Estimate in their email, click on "View Estimate" and from the public link, click Accept and Pay? When they click that, in the background Zoho would create the invoice record in the so that the payment would

    • Kaizen #125 Manipulating Multi-Select Lookup fields (MxN) using Zoho CRM APIs

      Hello everyone! Welcome back to another week of Kaizen. In last week's post in the Kaizen series, we discussed how subforms work in Zoho CRM and how to manipulate subform data using Zoho CRM APIs. In this post, we will discuss how to manipulate a multi-select

    • Easily track referrals with Zoho Forms

      Referral tracking can be a powerful way for businesses to understand where their leads are coming from. With Zoho Forms, tracking the referral sources of your leads is an easy and straightforward process. Here are some tips to help you make the most of

    • Add an email to an existing ticket is not working

      I noticed that in Zoho Desk the funcionality to add an email to an existing ticket is not working using the syntax [##12345##], has the method changed? In red is the syntax we use to add email to an existing ticket As you can see, he did not add the email

    • New CRM to Campaigns Sync Doesn't Continue Making Updates

      Changes made in CRM are not appearing in mapped fields in matching Campaign records after migrating to the new sync process. The only way we've found to get records to update is to call into Support and point out the problem. After convincing Support

    • Zoho Integration with UPS

      I have 2 questions: Firstly, is there a way to notify UPS that we have a package to collect once we have done the shipping label? Secondly, how do I get the tracking number and shipment method onto the Invoice and Package Slip for the customer? Than

    • Cannot log in to IMAP account as of last night

      Hey I've been using MFA with an authenticator for a while and have had to use application passwords for Outlook and Edison Mail on my Android devices. Last night the app passwords started to be rejected on my Android devices so I created new ones for

    • Low Stock View

      We use the Low Stock view frequently as a guide to inform us when to reorder items, but the view is misleading because it does not take into account Purchase Orders that have already been raised. Unless you are aware and check item by item, this can lead

    • Improve History Feature in Zoho Inventory

      At present there is a "history" tab on Zoho Inventory Items, however this only shows a date and time stamp along with the users name. It doesn't say what was changed. What is the value of this if you can't see what was changed? My Ideal is to include

    • Show backordered items on packing slip

      We send out a lot of large orders, and often there are one or two things backordered. How can I fix the packing slips to show quantity ordered  & quantity packed There should also be the ability to "ship" 0 of an item so the receiver knows that things

    • Document | Files

      The vendor "Partial matches" still not fixed here after years of putting up with having to select most vendors manually ! ( again, the banking "Transaction rules" would solve a lot of these issues ) Some unwanted, irrelevant pdf's also arrive. It would

    • books+POS+ tap to pay+ stripe

      So in the UK we now have tap to pay with stripe. So we can use the stripe app as a POS terminal. Brilliant news. Can we hope that the Books App might add this feature ASAP. It would be great to have one system rather than using the not very good Square

    • Canvas Form View - Client Script Page on load - Url params not working

      We have a custom module with a canvas page for form view. We have a button in Customers module to open this canvas page using invokeurl function. We send few parameters as in the URL as query parameters. https://crm.zoho.in/crm/orgxxxxxxxx/tab/CustomModule12/create/canvas/64333200000261xxxx?layoutId=643332000002605001&c=${Customers.Customer

    • Sending Recruit SMS's to Zoho Cliq - Or tracking in the Messages module in Recruit?

      Is there any way to send SMS Gateway messages in Recruit to ZOho Cliq? We use 2-way SMS massages a lot in Zoho Recruit to speed up communication with Candidates. However the only way to keep track of received SMS's is by keeping a look out for the Email

    • This mobile number has been marked spam. Please contact support.

      Hi Support, Can you tell me why number was marked as spam. I have having difficult to add my number as you keep requesting i must use it. My number is +63....163 Or is Zoho company excluding Philippines from their services?

    • Zohomail does not support additional fields in mailto links

      Hello, I set up Zohomail as default composer in Firefox according to manual here: https://www.zoho.com/mail/help/defaultcomposer.html#alink2 Later, I wanted to use this functionality to answer in a Linux mailing list thread using mailto link: mailto:xxxxx@kernel.org?In-Reply-To=%3C727o0521-q24p-s0qq-66n0-sn436rpqqr1p@example.com%3E&Cc=xxxxx%example.org&Subject=Re%3A%20%5BPATCH%20v2%28%29

    • Is it possible to set a customer context variable in Zobot

      Hi, I want to use a context variable to route users down different paths in my Zobot chat flow. I know I can do this when the user enters data. But I want to know if I can use a variable that is 'hard coded' on the card, that the user is unaware of. Use

    • Cannot change Blog Title

      There is nowhere to change the blog title. You can change the blog URL but that is making no difference to the text "Enter Your Post Title" am I missing something?

    • Kaizen #203 - Answering Your Questions | Handling API Limits and Error Responses

      Hi Everyone, Welcome back to yet another post in the Kaizen Series! We appreciate your keen participation in the 200th milestone celebration of the Kaizen series. We will continue to answer the queries we received through the feedback. When working with

    • How to verify website ownership with google search console

      Hi, I am having a free .in domain provided by Zoho I have created a website on it now I want to verify my ownership to google webmaster. Can you please help me how to do that.

    • Kaizen #89 - Color Coding using Client Script

      Hello everyone! Welcome back to another exciting Kaizen post. Today let us see how you can apply color codes to the List and Detail Pages of Zoho CRM using Client Script. Need for color code in Zoho CRM When you mark things with different colors as a

    • "SPF record exceed the allowed limit of 10"

      Hi, I was wondering if there were a "universal Zoho SPF record" that would allow all my configured Zoho services that email things to meet this limitation ? or do I have to have an entry for mail, com, billing, etc?

    • Zoho Mail android app update: Block & reject future emails, Report phishing, Spam alerts, Suspicious URL detection

      Hello everyone! In the most recent Zoho Mail Android app update, we have brought in support for the following features: Block & reject future emails Report Phishing Spam alerts in the mail details screen. Suspicious URL detection. Block & reject future

    • Animated GIF Images in Chat

      I know this seems to be a small feature request but in a recent Cliq update Zoho disabled autoplay for animated GIFs posted in Cliq conversations. We think this was not a good change. In our organization, animated GIFs in a chat play a role in expressing

    • I can't seem to login in to Mail Apps of MacOS /IOS

      Hi, i'm having trouble in signing in to mail apps from IOS. It's always come back to wrong passwords. But i already changed my password like 3 times. But still it says wrong credentials

    • Profile Image Showing Incorrectly in Zoho Mail

      Hi everyone, I’m facing a serious issue with Zoho Mail. The profile image showing for my email address is incorrect — it’s not my image. When I send an email to my Gmail account, it displays someone else’s image. This looks very suspicious and can make

    • I need access to my old email

      I need access to my old email bromzeman@zoho.com to verify it for forwarding. I can’t access the inbox to get the confirmation code. Please assist with recovery or forwarding. as you might already know, they made alot of the email addresses to have that

    • Set Defaults for Email Groups

      Is there a way to set defaults for all of the groups that I establish as a moderator? For example, I want every group I establish to have the following settings: 1. Moderator is <user> 2. User is <user>, <user> 3. Notifications for new group turned

    • LOGS FOR RECEIVED MAIL ( READ DATE & TIME)

      In Zoho mail we can extract the read logs of received mails so that we can see when we have read the mail and at what time & we have read it.

    • Domain verification probem

      Hello, i use a domain from Namecheap with hosting from Cinfu when i try to verify my domain on zoho i get "TXT Verification failure" i even tried the HTML verification and the code appears but also giving me the verification failure error.

    • Next Page