My outlook account notices some unusual IMAP Login from Microsoft at Redmond

Anonymous
2022-07-12T08:27:40+00:00

I'm noticed from Microsoft Account Service that my outlook account has been exposed some IMAP Logins from each of the IPv4 addresses at 13.101.0.0-13.101.255.255 since 2022-07-11 JST informed as "unusual activity".

And I found with using whois service that these IP may be managed by Microsoft and placed at Redmond city in US.

Yeah I changed PW in usual way but these access can't stop anyway, so I'm guessing this is a specification for Outlook service.

But at the same time I am afraid of some attacks to Outlook service or Microsoft's collection of users data.

Does Anyone know some information about these kinds of access?

I already used technical help service of online chats in Japan, but he said that he doesn't have some clear idea.

Notification

Thanks to any users to read this thread and report the same issue.

I guess you all are as anxious as I am, but I'd like you to just keep focus on the topic of "unusual activity" from 13.101.0.0/16 here.

While many attacks on login to some system will happen all the time around the world, Thus this case is unique in that it's coming from IPv4 addresses inside Microsoft.

And here we hope to solve this strange problem.

Thank you for your cooperation.

S.E.

Outlook | Web | Outlook.com | Account management, security, and privacy

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

0 comments
Answer accepted by question author
Anonymous
2022-07-19T22:42:18+00:00

User @Chezlong Just placed this on my forum post

https://answers.microsoft.com/en-us/outlook_com/forum/all/unusual-account-activity-from-ms-ip-addresses/974cc1c1-232f-44a2-b0eb-0f378fd2c801?page=5:

Finally got to talk to someone at MS- this was their reply:

Thank you for the information. Please be advise that Microsoft is aware of this known issue already. This started to happen even last week and we are already working with this matter. We even have created a ticket number for this issue while it is still happening.

The ticket number for the emerging issue is INC31680156.

So they are on it, but no idea when it will be fixed.

[EDIT] They also confirmed that the account was secure, no need to change passwords, etc

AND

Found the following on thread https://answers.microsoft.com/en-us/outlook\_com/forum/all/outlook-mail-account-unusual-activity/6cfb226f-8cd7-41ae-bd0a-a80d100af543?page=9

posted by user @Pierre-LucMorais:

I have looked for other means to communicate to MS and I found an “official” thread to post this problem. Your mile may vary but i’ve had a reply on my thread and encourage ppl to try using them as well ?

https://www.reddit.com/r/microsoft/comments/o22lfc/microsoft\_official\_support\_thread/

They’ve responded that it is a backend accessing the service and a known issue.

Hoping this helps

Was this answer helpful?

10 people found this answer helpful.
0 comments
Answer accepted by question author
Anonymous
2022-07-22T15:39:05+00:00

Outlook email users alerted to suspicious activity from Microsoft-owned IP address—
People turn amateur sleuths to discover that the source of all those sign-ins seems to be in Redmond
https://www.theregister.com/2022/07/21/outlook_sign_ins/
Article has an update at the end:

Updated at 09.33 UTC on 22 July 2022 to add:
Following publication of this article, Microsoft sent us a statement:
"We're working to resolve a configuration issue causing some customers to receive these notifications in error," said a Microsoft spokesperson via email.

Was this answer helpful?

2 people found this answer helpful.
0 comments

56 additional answers

Sort by: Newest
Most helpful Newest Oldest
  1. Anonymous
    2022-07-15T16:10:32+00:00

    FYI -

    I use the Outlook web portal on my computer in the Edge browser and also my iphone's mail app.

    My husband only uses the Spark email app.

    Was this answer helpful?

    1 person found this answer helpful.
    0 comments
  2. Anonymous
    2022-07-15T16:01:09+00:00

    A few people in this thread have said they don't use thunderbird. So far nobody has clearly stated that they use no email clients. I think the vulnerability is with the azure+outlook-servers end. It seems like most people in this thread use some kind of IMAP client, the timing of the attempts suggests that traffic that is destined for outlook might be going to someone's azure machines (who knows, maybe they are physically on the same computer) and being replayed to outlook. There must be more to it though, because SSL should theoretically prevent replay attacks. Maybe this could be Microsoft intentionally proxying the connection, but that isn't consistent with the logins that happen without coinciding with a client syncing, and it isn't consistent with Microsoft auto closing support tickets saying they are not responsible for what goes on at these IP addresses because they are for azure.

    Was this answer helpful?

    2 people found this answer helpful.
    0 comments
  3. Anonymous
    2022-07-15T15:30:47+00:00

    Confirmed this behavior on Windows 11 22000.795, Thunderbird 103.0b5, where as soon as Thunderbird launches and send login credentials to all linked accounts (2 Outlook, 2 Gmail), IMAP access from 13.101.*.* appears on my MS account, all marked as suspecious and denied. Then Thunderbird noted failed login for my MS account and ask for a new password, while this MS account and backup email address associated with it received the unusual login alert email on Thunderbird. Curiously this behavior does not appear on my other Outlook account logged into Thunderbird (yet). Still waiting for more information to decide whether to change password or not.

    While this could be an attempt by an actor to record Thunderbird login credentials and repeat those requests from an Azure server, as suggested by above, it could also be the results of incorrect server configuration on Mozilla's part. Still, this suggests that there may be security breaches in Microsoft or Mozilla. I don't have a MDN account, so hopefully MS engineers can notify Mozilla of this issue.

    Was this answer helpful?

    0 comments