Short answer
Change your password immediately, then review your mail and account settings on Yahoo’s Account security page. Attackers often change auto-forwarding, filters, the reply-to address, sending name, signature, vacation responder and blocked addresses — check each one. Revoke app passwords, remove any recovery email or phone you didn’t add, and turn on 2-step verification. If you can’t sign in at all, use the forgot-password option on Yahoo’s sign-in page; for further help Yahoo points to its Customer Care.
Signs of a hacked Yahoo account
- Password no longer works, or you see sign-ins you don’t recognise in recent activity.
- Contacts receive spam or strange messages from your address.
- Missing emails, new filters or a forwarding address you didn’t set.
Secure it now
- Change your password to a strong one you don’t use elsewhere.
- Open the Account security page and review recent activity and connected devices.
- Revoke app passwords — Yahoo advises this after a security-related password change — and delete any you don’t recognise.
- Remove recovery email addresses and phone numbers you didn’t add.
Check the mail settings attackers change
- Auto-forwarding: a forward to an unknown address means someone is still getting copies.
- Filters that delete or move mail (for example from your bank).
- Reply-to address, sending name, default “From” address and signature.
- Vacation responder and blocked addresses.
If you can’t sign in
Use the forgot-password option on Yahoo’s sign-in page with your recovery phone or email. If that doesn’t work, Yahoo’s help centre directs you to Customer Care. Be wary of “Yahoo support” phone numbers found in ads — use only links from help.yahoo.com.
Lock it down
- Turn on 2-step verification so a new device needs a code.
- Keep your recovery phone and email current, and secure the recovery email too.
- Accounts that reset to this address (banks, shops, social media) are at risk — change their passwords: 15-minute security checklist.
- Our hacked account recovery service works through official channels.
Frequently asked questions
What should I do first if my Yahoo account is hacked?
Change the password immediately, then check forwarding, filters and recovery info on the Account security page.
Why is my Yahoo mail still being read after I changed the password?
Check auto-forwarding to unfamiliar addresses and revoke app passwords — Yahoo lists both among the steps after a hack.
How do I recover a Yahoo account I can’t sign in to?
Use the forgot-password option on the sign-in page; if it fails, Yahoo points to its Customer Care.
Does Yahoo have 2-step verification?
Yes. Yahoo recommends it: every sign-in from a new device or browser then needs a code as well as your password.
Sources: Yahoo Help — recognize a hacked Yahoo Mail account, Yahoo Help — secure your Yahoo account