Last week a number of Comcast customers logged into their Xfinity email accounts only to discover that they had been hacked. The source of these widespread attacks seems to be an exploit that allows an attacker to bypass Xfinity two-factor authentication (2FA) for Xfinity accounts.
Hackers appear to be using a privately circulated tool that bypasses the one-time-passcode (OTP) used in 2FA. Essentially, your account will not send the 2FA code to you. Instead, the hackers will get it, cutting you out of the loop.
First, the attackers compromise an Xfinity email account by using stolen passwords from the Dark Web. From there, they login with the stolen passwords and use the private 2FA bypass tool to get around phone verification.
After that, the password is reset, and any backup or secondary emails are changed to one the attacker controls.
Once they have access to the Xfinity email, hackers can use this email to attempt to password reset other services with the ‘Forgot my Password’ feature.
They’ve been observed using this method to compromise Drobox, Evernote and even cryptocurrency exchange accounts such as Coinbase and Gemini.
Comcast hasn’t released an official statement as of this correspondence, and its unknown how many accounts were compromised. If you have a Comcast email account, we recommend that you immediately update your password and check the recovery email and 2FA information you have on file. Reach out to Comcast Xfinity support if necessary.
It is also a good idea to review your other accounts and services for compromise.
A few important things to note in these attacks:
- 2FA was not enough. The hackers bypassed it.
- Those who regained access to their accounts did so because they noticed a change in 2FA by monitoring their email accounts.
- The accounts were originally compromised via “credential stuffing” which uses Leaked Passwords found on the Dark Web
These are all common pain points for which our 3rd party security assessments identify.
If you have any questions or concerns, please do not hesitate to contact us.