Received Azure: Activated Severity: 3 SigAlert-4255635-A16 email

Question

I received an email that starts:
NOTE: This is a degraded email experience. That means the formatting may be off or details could be missing. For more information on the degraded email experience, [www.aka.ms/armemail]read here.

 Your Azure Monitor alert was triggered

Azure monitor alert rule SigAlert-4255635-A16 was triggered for inv4255635 at March 16, 2026 11:38 UTC.

Concurrently, my credit card provider flagged with a fraud alert for an amount close to what was in this email

Answer 1

Hello Ken Loewen, What you’re describing closely aligns with a known scam pattern involving Azure alert emails.

In these cases, attackers first gain access to an Azure subscription and then deliberately configure alert rules to send notifications to external email addresses (such as yours). They subsequently trigger those alerts. While the emails are technically generated by Azure, the alert message content itself is authored by the attackers.

These emails typically include alarming language such as:

• references to a “Fraud Prevention System” or “Windows Defender,”
• warnings about large, suspicious charges,
• threats of account suspension, and
• a so‑called “Fraud Resolution” or “Support Hotline” phone number.

The objective is to pressure recipients into calling that number, where the scam continues.

Important guidance:

• Do not call any phone number mentioned in the email.
• Do not click any links included in the message.
• Simply delete the email.

It’s worth noting that these messages can appear convincing because they are sent from legitimate Microsoft email infrastructure. However, Microsoft does not include phone numbers or urgent call‑to‑action language like this in genuine Azure alert notifications.

Reference: https://malwaretips.com/blogs/microsoft-azure-alert-was-triggered-scam-exposed-investigation/

If the provided information helped, kindly consider marking the answer as "Accepted" and "Upvote" it. This helps other community members who may encounter a similar issue in the future.

If you have any queries, please feel free to reach out us.

Thanks,

Answer 2

Hi Ken,

Recently there have been malicious Azure Monitor Alert messages going out and there is good chance that is what you are receiving. DO NOT call any phone number(s) in the email messages.

If you want you can post one of the messages as a comment (remove your email address for privacy reasons) and I will tell you if it is scam message or legitimate.

It appears what is happening is bad actors get access to an Azure subscription, set up Alerts with potential victim's email address (your email) set as recipient, then trigger alert. In the text of the alert they mention things like Fraud Prevention System, Windows Defender, some substantial $ amount, potentially unauthorized charge, account suspension, Fraud Resolution Hotline, etc., and their goal is for you to call a phone number.

DO NOT call any phone number in the email and DO NOT click on any links. They want you to call them so they can scam you.

Please click Accept Answer and upvote if the above was helpful.

Thanks.

-TP