Hackers find way to access Gmail, Outlook, or Yahoo inbox

Iranian state-sponsored hackers have discovered ways to infiltrate the Gmail, Yahoo, and Outlook inboxes of at least two dozen high-profile users and download their content, according to a report from the Google Threat Analysis Group (TAG).

The government-backed group known as Charming Kitten originally developed a hacking tool called Hyperscape in 2020 and has used it to orchestrate the recent cyberattacks. TAG was able to get a hold of a version of this tool for analysis, TechRadar reported.

Google explained that the attack works in a stealth fashion where there is no typical hacking ritual, such as tricking a user into downloading malware. Instead, hackers control the tool from their end, taking advantage of vulnerabilities, such as compromised account credentials or stolen session cookies, in order to access an account.

While this particular cyberattack may have been politically motivated, Google is clearly interested in how these vulnerabilities might be used by others in the future.

A recent report from Sophos details how cookie stealing is among the latest trends in cybercrime. Hackers use the method to bypass security measures such as multifactor authentication and access private databases.

In this case, once logged into the email account, hackers use the tool to trick the email service into thinking a browser is outdated, which then switches it to a basic HTML view. Then it changes the inbox language to English and opens emails individually to begin downloading them in a .eml format. The hackers then mark any opened emails as unread and delete any warning emails, set the inbox back to its original language, and exit.

Despite its seemingly smooth execution, Google has learned a lot about the cyberattacks and has notified all of the known accounts that were affected through its Government Backed Attacker Warnings. TAG has deciphered that the tool was written in .NET for Windows PCs and noted attacks might work differently in Yahoo and Outlook inboxes. At this time, the security group has only tested the tool in Gmail.