Impersonation/Identity theft.
The use of an account without the permission of knowledge of the owner is considered can be considered as an identity theft or impersonation. This is especially true if the attacker uses the stolen identity to interact with others who do not have the knowledge of this attack.
Indications:
- Unknown activity and usage of the account.
- Messages with harmful URLs or OTPs.
- Changed password/locked out account.
- Logins from unusual locations and IPs.
- Modifications in profile details without prior knowledge.
Steps to prevent:
- Keep changing the account password every few months.
- Enable security features such as 2FA or 3FA (biometrics).
- Regular checks on profile information and login locations.
- Do not click arbitary URLs or links from unknown origins.
- Checks for database breaches using HaveIBeenPwned or similar tools on routine bases.
- Complex password policy and use of different usernames and emails.
Mitigation:
- Notify close relatives, friends and work-mates to not interact with any links/messages from the suspicious account.
- Try reseting the password or contacting the website support if possible.
- In case of very sensitive websites, immediate notification to superiors or administrators should be sent.
- If the account is not required that often, a new fresh account can sometimes be the best thing to do.