The LINE theft disaster is spreading! Could voicemail be a security vulnerability? Quickly check if you've implemented the five key protections.

Taiwan experiences a surge in reports of LINE accounts being hijacked, mostly affecting users of Taiwan Mobile. Rumors suggest hackers intercepted verification codes by exploiting voice mailboxes with unchanged passwords. Authorities are actively investigating and urge the public to change their passwords immediately and enable two-factor authentication to enhance cybersecurity.

LINE hijacking incidents widely reported, Taiwan Mobile and LINE are investigating

Since the evening of March 31, 2026, numerous netizens across Taiwan’s major social platforms have reported abnormal activity on their LINE accounts.

Many users noted that, without any action on their part, their accounts were suddenly forcibly logged out, and they could no longer log in. During this period, their phones even received suspicious verification SMS messages. Additionally, most victims of account hijacking are Taiwan Mobile users.

In response, LINE officials told Nownews Today News that they have launched an investigation into the reported account hijacking issues and will continue to closely monitor the platform’s overall security.

Taiwan Mobile also explained that after an initial review, most of the affected users were former Taiwan Star customers prior to the merger. The operations team is now handling the situation and has proactively asked these users to change the default password of their voice mailboxes.

Rumors claim voice mailboxes are a cybersecurity vulnerability; security firms provide analysis

Regarding how hackers managed to breach users’ accounts on a large scale, it is widely believed on social media that the main vulnerability lies in the voice mailbox feature provided by telecom operators.

CyberShield Security told Nownews Today News that attackers did not employ complex techniques. Instead, they exploited the common practice where many users never disable or change the default voice mailbox password.

In scenarios targeting voice mailboxes, hackers primarily use automated scripts to input users’ phone numbers and attempt to log into LINE. The system then automatically sends an SMS with a verification code. If the attacker chooses the voice verification option, the system will call and read out the password.

When users miss this call, the voice message containing the verification code is stored in the telecom provider’s voice mailbox. Since many users’ mailbox passwords remain at factory defaults like 0000 or 1234, hackers only need to dial the remote listening line, enter the phone number and default password, and they can retrieve the verification code, log into the account, and remove the original user.

After hijacking an account, hackers often send scam messages requesting loans or links to investment scams among friends. These legitimate accounts can also become tools for overseas criminal groups to launder money.

However, neither LINE nor Taiwan Mobile has confirmed the rumor that voice mailbox vulnerabilities are the cause. The investigation results are awaited for confirmation.

Five security measures to make LINE accounts safer

Although the exact cause of the LINE hijacking incidents has not been publicly disclosed, users can take several basic steps to improve their account security:

👉 Turn off or change your voice mailbox password

If you are concerned that your voice mailbox could be a security weak point, you can use your telecom provider’s app or customer service hotline to disable the voice mailbox feature entirely or change the password to a complex combination, blocking remote access.

👉 Enable two-step verification and account linking

Be sure to activate the 2-step verification feature within the LINE app. LINE recommends users go to the settings page to verify that their phone number and email are fully set up. Additionally, binding your Apple or Google account is advised, so that if an incident occurs, multiple authentication methods are available to recover your account.

👉 Stay alert for suspicious verification calls

If you notice unknown verification calls on your phone, immediately check your voice mailbox. If there are abnormal voice messages, delete them and change your password. If your account has already been compromised, first fix the voice mailbox password vulnerability before proceeding with account recovery steps to prevent repeated hijacking.

👉 Adjust device login permissions

In the LINE app’s “My Account” settings, temporarily disable the “Allow login from other devices” option. This prevents hackers from attempting to log in via computers or tablets. If you need to use the desktop version, you can keep this option enabled but turn off “Use password to log in” and instead only log in by scanning a QR code with your phone, greatly enhancing login security.

👉 Avoid clicking unknown links

Do not click on suspicious phishing SMS messages or links, and do not disclose sensitive information such as your LINE account password on unfamiliar websites.

• Further reading: Line Pay Money explained for beginners: registration and activation guide, offers, and bank fee overview