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
    2022-07-14T17:03:28+00:00

    Same here. This is probably happening to a lot of people. Some Microsoft owned IPs successfully signed in and synced with IMAP.

    13.101.57.232
    13.101.57.43
    13.101.57.174
    13.101.60.200
    13.101.61.71
    13.101.57.20

    No 2fa or app-password but I have thunderbird in common with the last user. Is anyone experiencing this while not using any email client?

    I couldn't find this 13.101.0.0 range in the list here https://www.microsoft.com/en-us/download/confirmation.aspx?id=56519 but I don't know if that proves it is not azure, maybe the list is incomplete

    The attempts have not stopped as of a few minutes ago. I hope someone at Microsoft is thinking of turning off these vm's soon, if it is a malicious azure user.

    Was this answer helpful?

    1 person found this answer helpful.
    0 comments
  2. Anonymous
    2022-07-14T14:44:52+00:00

    Another one to add to the list... Yesterday morning (July 13th), my Thunderbird IMAP connection refused to work when I got up... I also already had 2FA setup... I then went to check the activity and noticed a ton of successfull and unsuccessfull attempt (all from "13.101.70.247") - (most were in IMAP, but one was a regular browser connection with wrong password) I immediately changed my main password, and resetted my APP Password as well.

    However, less than 1 hour later, there was already a new "successfull login" via IMAP!

    What bothers me is that even at night, when NOT A SINGLE computer are online it still happens (I do not use any cell phone or mobile devices to access the internet... and I never touched or used any "AZURE" service either)

    I assumed the APP Passwords had been compromised so I wanted to setup Oauth with Thunderbird via IMAP... but Microsoft only supports IMAP via "APP Password"...

    So I'm not sure what the actual solution is...

    Was this answer helpful?

    2 people found this answer helpful.
    0 comments
  3. Anonymous
    2022-07-14T11:29:54+00:00

    Same here. Same protocol, same IP range. 2FA was already configured.

    @Fatima_J please request investigation from technical engineers!

    Was this answer helpful?

    3 people found this answer helpful.
    0 comments