VULNpocalypse
LowBreach / campaignMonitoring

SoftBank took My SoftBank, My Y!mobile and My Menu websites offline after an unauthorized access attempt

SoftBank detected an unauthorized access attempt on My SoftBank systems on 17 Oct 2026 and shut its customer websites for four days. No data leak announced.

Published
Updated
Exploitation
Attempted. SoftBank detected abnormal activity and blocked suspicious outbound routes; it has not announced any data access or leak

What happened

This is a SoftBank Corp. incident, separate from the October ransomware attack on its cloud subsidiary IDC Frontier.

  • 17 October 2026 (Saturday): SoftBank’s monitoring system automatically detected abnormal activity in some systems related to My SoftBank, its customer account site. SoftBank says a third party had attempted unauthorized access. It shut down part of the related systems and blocked suspicious external communication routes (SoftBank press release).
  • 17 October, 08:00: the web versions of My SoftBank, My Y!mobile and My Menu were taken offline as a safety measure. The apps stayed available (SoftBank press release).
  • 19 October: SoftBank announced the attempt, about two days after the sites went down (SoftBank press release; smhn.info).
  • 21 October, about 21:00: the My SoftBank website came back, per a support notice dated 22 October that repeats the access attempt as the reason (SoftBank support notice).

What is not disclosed: how the attempt was made, whether the attacker got any data, which “related systems” were involved, what the blocked external routes were used for, and who was behind it. SoftBank’s notices do not say whether customer information was accessed, and do not ask users to change passwords (smhn.info).

Am I affected?

  • Customers. No SoftBank notice so far tells customers to act, and none says customer data was accessed. Check SoftBank’s own news pages for any follow-up, not links sent to you.
  • Password reuse. SoftBank has not said what the attempt targeted. A 2014 My SoftBank incident was a list-based login attack, using IDs and passwords likely stolen elsewhere, that hit 344 accounts (smhn.info). If your SoftBank ID password is also used on another site, you are the kind of account that attack works on.

What to do now

  1. Use the app or a typed address for My SoftBank. The web outage was a good cover story for phishing that says “please log in again” or “verify your account after the maintenance”. SoftBank’s notices about this incident do not ask customers to do anything.
  2. Give the SoftBank ID a password used nowhere else, if it currently shares one with another site.
  3. Watch for a follow-up. SoftBank has not published a final report. This advisory will be updated if it announces that customer data was accessed.

Sources