ICLOUD Outlook Storage Scam Spreads Malware Via Fake Emails

A new phishing scam has emerged that targets Outlook users by claiming their ICLOUD storage is almost full. This convincing fake notification states that incoming emails have failed delivery as a result. It then directs victims to malicious attachments disguised as the undelivered messages. Security experts have identified this as a campaign spreading the dangerous Agent Tesla remote access Trojan (RAT). Here’s what you need to know about this scam and how to protect yourself.

Overview of the ICLOUD Outlook Storage Scam

This phishing scam starts with an email that impersonates a warning from ICLOUD about your Outlook email storage. The subject line reads something like “Warning: Mailbox ICLOUD size notification for [your email] (Undelivered Mails Attached).”

The email claims that your ICLOUD-linked Outlook account is nearly full at 96.89% capacity. It states this has caused multiple incoming messages to fail delivery. The scam email goes on to say these undelivered emails are attached, and you should open them to either allow delivery or delete any unwanted messages.

However, the attachments are actually malicious Office documents infected with the Agent Tesla RAT. Once opened, this remote access Trojan secretly infects your computer and allows cyber criminals full access to steal data, install more malware, and spy through your webcam and microphone.

The scam email is designed to look like legitimate notifications from ICLOUD and Outlook. But make no mistake – this is a phishing attempt aimed at stealing personal information and compromising devices with malware.

How the ICLOUD Outlook Storage Scam Works

This scam starts like many phishing attempts – with an email seemingly from a trusted source that urges you to open malicious attachments. Here’s a closer look at how it works:

1. You receive an email claiming to be from ICLOUD support. The subject line and content are crafted to appear as if ICLOUD is alerting you about an Outlook storage issue. Phrases like “ICLOUD linked to Outlook storage” and mentions of undelivered messages are used to add legitimacy.
2. The email states your account is nearly full, causing failed deliveries. By claiming your storage is at 96.89% capacity, the scam adds urgency to open the supposed undelivered messages. This is a common phishing tactic to get users to act quickly without thinking.
3. Malicious Office documents are attached as the “undelivered emails.” Instead of actual messages, the attachments are Excel, Word, or Powerpoint files infected with the Agent Tesla RAT. The extensions may be hidden to further disguise them.
4. Users are instructed to open the attachments to deliver the emails. The scam email tells you to open the files to either allow the fake messages to be delivered, or delete any unwanted ones. This tricks you into installing the malware.
5. Agent Tesla infects your computer if you enable macros. The malicious Office documents contain macros that automatically download and install the RAT when enabled. Agent Tesla then has full access to your files, webcam, microphone, and more.
6. Your personal data is stolen and more malware downloaded. With its remote access, the attackers can silently steal account credentials, financial information, and any other sensitive data. More dangerous malware may also be installed.

This social engineering attack exploits a perceived problem with your Outlook account to trick you into infecting yourself. The urgent tone and legitimate-looking email are designed to bypass scrutiny and get you to open the malicious attachments without realizing the consequences.

What to Do if You Open the Malicious Attachments

If you receive this phishing email and unfortunately open the infected Office document attachments, here are the steps you should take right away:

• Disconnect your device from the internet. Unplug your affected computer from the network immediately to prevent further malware communications. Disable WiFi as well.
• Scan for malware with antivirus software. Run a full system scan with Malwarebytes to detect Agent Tesla and any other infections. Quarantine or delete any malware it finds.
• Reset your Outlook account password. Even if no emails were accessed, resetting your password prevents the attackers from logging in. Enable 2FA if possible.
• Contact your email provider. Alert Microsoft, ICLOUD, or any other provider about the phishing attack. They may have additional security recommendations.
• Check for unauthorized activity. Review account statements and credit reports to spot any suspicious charges or activity indicating stolen data. Place fraud alerts if needed.
• Wipe your device and reinstall the OS. For severe infections, the nuclear option is performing a factory reset and wiping your hard drive before reinstalling the OS. Backup personal files first.
• Install antivirus and anti-phishing software. Beef up your security with robust cybersecurity solutions to prevent future attacks. Use tools that block phishing websites and emails.

If Agent Tesla or other malware was installed, take steps immediately to prevent worse damage. Catching and removing the infection quickly can mitigate the fallout. You may have to take more drastic measures though, like wiping your device, if the RAT spent time actively on your system.

Is Your Device Infected? Run a Free Malware Scan

Slow performance, constant pop-ups, or strange behavior? These are classic signs of a malware infection. A quick way to check is to scan your device with Malwarebytes Free, one of the most trusted malware removal tools available. If you only visited a scam page and didn’t download or install anything, this scan is optional.

The free version detects and removes the most common threats, including:

• Adware — the cause of those annoying pop-ups
• Browser hijackers — unwanted redirects and changed homepages
• Trojans and spyware — hidden programs stealing your data
• Potentially unwanted programs (PUPs) — software you never asked for

👉 Select your device below — Windows, Mac, or Android — then follow the simple steps to download Malwarebytes, scan your system, and remove any threats it finds. The scan usually takes 5 to 20 minutes.

Malwarebytes for WindowsMalwarebytes for MacMalwarebytes for Android

Run a Malware Scan with Malwarebytes for Windows

Malwarebytes is one of the most popular and trusted anti-malware tools for Windows — and it’s completely free for removing infections. It catches threats that many antivirus programs miss, including adware, browser hijackers, and trojans. Follow the steps below to scan your PC and remove what Malwarebytes finds.

1. Download Malwarebytes

   Click the button below to download the latest version of Malwarebytes for Windows from the official source. The free version is all you need — it will scan your computer and remove adware, browser hijackers, and other malicious software at no cost.

   

   Malwarebytes Free for WindowsScans and removes malware at no cost

   Download MalwarebytesOfficial installer for Windows 11 and 10. Your download starts right away.Want real-time protection? See Malwarebytes Premium

2. Install Malwarebytes

   When the download finishes, open your Downloads folder and double-click the MBSetup file. If Windows shows a User Account Control pop-up, click “Yes” to allow the installation.

   

3. Follow the On-Screen Prompts to Install Malwarebytes

   The setup wizard will walk you through a few quick screens:

   • Choose where you’re installing the program — “Personal Computer” or “Work Computer” — then click Next.

     

   • Malwarebytes will now install on your device. This usually takes under a minute.

     

   • When installation is complete, the “Welcome to Malwarebytes” screen will open automatically.

     

   • On the final screen, click Open Malwarebytes to launch the program.

     

4. Optional: Check for rootkits with a Custom Scan

   You don’t need to change any settings for a normal scan. The standard Threat Scan in the next step is enough for most problems, so you can go straight to it.

   If you also want to check for rootkits, use a Custom Scan. In current versions of Malwarebytes, rootkit scanning is only available there:

   1. On the Scanner tile, click the three-dot menu and select Advanced Scan.
   2. Choose Custom Scan. In its options, check Scan for rootkits.
   3. Select your system drive (usually C:\) as the location to scan, then start the scan. It takes longer than a Threat Scan.
   4. When it finishes, review and quarantine the results as described in the steps below.

   Rootkit scanning isn’t available on Windows devices with ARM processors.

5. Start the Scan

   Click the blue Scan button. Malwarebytes will automatically update its virus database and start checking your computer for malware.

   

6. Wait for the Scan to Finish

   The scan checks your entire system for browser hijackers and other malicious programs, so it can take 5 to 20 minutes depending on your computer. Feel free to do something else — just check back occasionally to see the progress.

   

7. Quarantine the Detected Threats

   When the scan is done, you’ll see a list of everything Malwarebytes found — malware, adware, and potentially unwanted programs. Click the “Quarantine” button to remove all of them at once.

   

   Malwarebytes will now remove the malicious files and registry entries and move them safely into quarantine.

   

8. Restart Your Computer

   Some threats can only be fully removed after a reboot. If Malwarebytes asks you to restart, click Yes. Once you’re logged back in, Malwarebytes has finished removing the threats it found.

   

When the scan is done, check whether the problems you noticed have stopped. If they continue, see the options below.

Keep your PC protectedStop the next infection before it starts

If your antivirus let this threat through, it may not be enough on its own. Malwarebytes Premium adds real-time protection that blocks malware, ransomware, and malicious websites before they can infect your computer.See Malwarebytes Premium

If you are still having problems with your computer after completing these instructions, then please follow one of the steps:

• Run a computer scan with ESET Online Scanner
• Ask for help in our Windows Malware Removal Help & Support forum.

Run a Malware Scan with Malwarebytes for Mac

Malwarebytes for Mac is a free on-demand scanner that removes the malware other security software tends to miss — adware, browser hijackers, and unwanted programs included. Cleaning an infected Mac with Malwarebytes has always been completely free, and it’s our go-to recommendation. Follow the steps below to scan your Mac and remove what Malwarebytes finds.

1. Download Malwarebytes for Mac

   Click the button below to download the latest version of Malwarebytes for Mac.

   

   Malwarebytes Free for MacScans and removes malware at no cost

   Download MalwarebytesOfficial installer for macOS. Your download starts right away.Want real-time protection? See Malwarebytes Premium

2. Open the Malwarebytes setup file

   When the download finishes, open your Downloads folder and double-click the setup file to begin the installation.

   

3. Follow the On-Screen Prompts to Install Malwarebytes

   The Malwarebytes for Mac Installer will guide you through a few quick screens. Click “Continue” and keep following the prompts until the installation completes.

   

   

   

   When the installation is complete, Malwarebytes opens to the Welcome to Malwarebytes screen. Click “Get started“.

   Malwarebytes needs Full Disk Access to check your whole Mac. When it asks, open System Settings > Privacy & Security > Full Disk Access, turn on Malwarebytes (it may be listed as Malwarebytes Protection), and confirm with your password or Touch ID. Then return to Malwarebytes. On macOS Monterey and earlier, this setting is in System Preferences > Security & Privacy > Privacy.

4. Select “Personal Computer” or “Work Computer”

   Malwarebytes will ask what type of computer you’re installing it on. Click either Personal Computer or Work Computer, whichever applies.
   

5. Start the Scan

   Click the “Scan” button. Malwarebytes will automatically update its detection database and begin checking your Mac for malware.
   

6. Wait for the Scan to Finish

   Malwarebytes will scan your Mac for adware, browser hijackers, and other malicious programs. This can take a few minutes, so feel free to do something else — just check back occasionally to see the progress.
   

7. Quarantine the Detected Threats

   When the scan is done, you’ll see a list of everything Malwarebytes found. Click the “Quarantine” button to remove all the threats at once.
   

8. Restart Your Mac

   Malwarebytes will now remove all the malicious files it found. Some threats can only be fully removed after a reboot — if Malwarebytes asks you to restart, allow it. Once you’re logged back in, check whether the problems you noticed have stopped. If they come back, save the scan report and ask for help in our forum.
   
   

If the problems you noticed continue after the scan, see the options below.

Keep your Mac protectedStop the next infection before it starts

If your Mac got infected, its built-in protection may not be enough on its own. Malwarebytes Premium for Mac adds real-time protection that blocks malware and adware before they can infect your Mac.See Malwarebytes Premium

If you are still experiencing problems while trying to remove a malicious program from your computer, please ask for help in our Mac Malware Removal Help & Support forum.

Run a Malware Scan with Malwarebytes for Android

Malwarebytes for Android scans your phone or tablet for malware, adware, and potentially unwanted apps. The free version scans only when you start a scan. Real-time protection, which checks apps automatically, is part of the paid Premium version.

1. Download Malwarebytes for Android.

   You can download Malwarebytes for Android by clicking the link below.

   

   Malwarebytes for AndroidScans your phone and removes malware at no cost

   Get Malwarebytes for AndroidOpens Google Play in a new tab.Want real-time protection? See Malwarebytes Premium for Android

2. Install Malwarebytes for Android on your phone.

   In the Google Play Store, tap “Install” to install Malwarebytes for Android on your device.

   

   When the installation process has finished, tap “Open” to begin using Malwarebytes for Android. You can also open Malwarebytes by tapping on its icon in your phone menu or home screen.
   

3. Follow the on-screen prompts to complete the setup process

   When Malwarebytes opens, it walks you through a short setup. Tap Get started and follow the prompts. If you see an offer for a trial or a paid plan, read it before you accept. You can skip it and keep using the free scanner.

   Malwarebytes will ask for permission to access the files on your phone so it can scan them. Tap Allow, or turn on the permission in the Android screen that opens, then return to Malwarebytes.

4. Run a scan with Malwarebytes for Android

   On the main screen, tap Scan now. In some versions, you open the menu, tap Scanner, and then tap Run a scan.

5. Wait for the Malwarebytes scan to complete.

   Malwarebytes will now start scanning your phone for adware and other malicious apps. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
   

6. Remove the detected apps.

   When the scan has been completed, you will see a list of the threats that Malwarebytes for Android has detected. Next to each detected item, tap the menu icon (three dots), then choose to uninstall the app or delete the file. Android then asks you to confirm. Tap OK or Uninstall to remove the app.

7. Restart your phone.

   When the detected apps are removed, restart your phone if Malwarebytes asks you to. Then check whether the problems you noticed have stopped.

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If the problems you noticed continue after the scan, see the options below.

Keep your phone protectedStop the next infection before it starts

Malwarebytes for Android Premium adds real-time protection that blocks malicious apps and scam links before they can harm your phone.See Malwarebytes for Android

If you are still having problems with your phone after completing these instructions, then please follow one of the steps:

• Ask for help in our Mobile Malware Removal Help & Support forum.
• Only as a last resort, reset your phone to factory settings. Read the warning below first.

A factory reset erases everything on your phone. Your apps, photos, files, and settings are deleted, so use it only if the problem continues after the steps above and after you’ve asked for help. Before you reset:

• Back up your photos, videos, files, and messages, for example to your Google account or a computer.
• Make sure you know your Google account email and password. The phone asks for them after the reset. If you changed the password recently, Google recommends waiting 24 hours before you reset.
• On a Samsung phone, also make sure you know your Samsung account password.
• If you use an authenticator app for two-step verification, move your accounts to another device or save your backup codes first.

On a Google Pixel, go to Settings > System > Reset options > Erase all data (factory reset). On a Samsung Galaxy phone, go to Settings > General management > Reset > Factory data reset. Menu names differ on other phones, so check your manufacturer’s support site.

Stay Protected: Block Ads and Malicious Sites

No scan can prove a device is completely clean, so it helps to block threats before they reach you. Most infections start with a malicious ad or a fake download button — so blocking them at the source is your best defense.

We recommend AdGuard, which blocks malicious ads, phishing pages, and dangerous redirects before they can reach you.

👉 Download AdGuard and browse safely

Frequently Asked Questions about the ICLOUD Outlook Storage Scam

What is the ICLOUD Outlook storage scam?

This is a phishing scam where victims receive an email claiming their Outlook account linked to ICLOUD is almost full. It states this caused undelivered messages that are attached to the email. However, the attachments contain malware.

How does the scam email look believable?

The scam uses official logos and urgent wording about failed deliveries due to full storage. This tricks users into thinking ICLOUD sent it. The attachments are disguised as undelivered messages.

What happens if I open the attachments?

The Office document attachments contain macros that install the Agent Tesla remote access Trojan. This gives hackers control of your computer to steal data, install more malware, and spy through your webcam.

Should I click any links in the scam email?

No, the email contains no legitimate links. Any links are likely phishing sites or additional malware. Never click links or attachments from suspicious emails.

How do I tell this is fake and not real ICLOUD mail?

Real notifications from ICLOUD would not claim you have undelivered messages in a separate attachment. Unexpected attachments are a red flag. ICLOUD also doesn’t mention macros.

What should I do if I enabled macros from the attachment?

Immediately disconnect your device from all networks. Run antivirus scans to remove any malware installed. Also reset your Outlook password and contact ICLOUD support about the phishing attack.

How can I protect myself from this scam?

Watch for urgent emails with attachments from ICLOUD or Microsoft. Verify messages by contacting support. Never enable macros in documents from people you don’t know. Use antivirus software and be cautious.

What should I do if I think someone is accessing my account?

If you see unauthorized activity, immediately change your Outlook password and enable two-factor authentication. Review account statements for any unknown charges indicating stolen financial data. Place fraud alerts on your name if identity theft is suspected.

Conclusion: Stay Vigilant Against Outlook Phishing Scams

Email scams targeting popular services like Outlook continue to grow in sophistication. This ICLOUD storage phishing campaign leverages timely social engineering to bypass user defenses. The urgent tone plus official-looking message tricks unwitting victims into installing sophisticated malware like Agent Tesla.

Stay vigilant against these types of phishing attempts. Warning signs include unexpected attachments, threats about account access being lost, and requests to enable macros. When in doubt, contact the service provider directly to confirm strange emails. Backups, antivirus software, and password managers are also essential precautions against phishing.

With attention and sound cybersecurity practices, users can better identify and stop these malicious attacks in their tracks. Don’t let emergent phishing scams like this Outlook impersonation fool you – be cautious about what links you click and attachments you open. Your data and device security depend on it.