Google Issues Urgent Security Alert After Hackers Attempt Large-Scale Theft from 2.5 Billion Gmail Accounts

Google has sent out a critical warning to Gmail users all around the world after identifying a huge data theft attempt that may have put almost 2.5 billion accounts at risk. Google's Threat Intelligence organisation stated that a hacker group tracked as UNC6395 is linked with the attack, which happened between August 8 and August 18, 2025.

The hackers managed to get in because they had stolen authentication credentials that were tied to third-party apps and services that integrate with Gmail. This weakness in the system let them take a lot of information, like usernames, email addresses, login information, and in some cases, even credentials for other cloud services. Even if the hackers tried to cover up what they did, Google stated that records are still available to help find the accounts that were affected.

Google has made it clear that hackers did not get into Gmail's main servers. The problem originated from third-party integrations.  But because the hack was so big, Gmail users all across the world could be in risk. It's not clear how many accounts were exploited, but the huge number of these accounts makes this one of the biggest security problems in recent years.

Google is advising everyone who uses Gmail to act quickly to protect their accounts.To make your account even safer, the business recommends altering your Gmail password and turning on two-factor authentication (2FA). Users should also look at their Gmail login history to see if anything strange has happened and go through their accounts carefully to find any suspicious third-party apps and delete anything they don't know about. It's also vital to change and update any credentials that are tied to Gmail, including stored login information or API keys. Lastly, Google cautions to be on the lookout for phishing emails, as hackers may try to use stolen information to get users to give them even more information.

Google has already revoked the compromised tokens and is working closely with partners to find out what happened. Meanwhile, The company states that users shouldn't delay to protect their accounts. Taking preparations in a timely manner can greatly lower the chance of more damage from this large-scale attack.

Information referenced in this article is from Money Control