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When MFA isn't MFA, or how we got phished

retool.com

31–40 of 287 posts

Re: When MFA isn't MFA, or how we got phished

#31
Fantastic write-up. Major props for disclosing the details of the attack in a very accessible way.

It is great that this kind of security incident post-mortem is being shared. This will help the community to level-up in many ways, specially given that its content is super accessible and not heavily leaning on tech jargon.

Re: When MFA isn't MFA, or how we got phished

#32
post #22

Very sophisticated attack, I would bet most people would fall for this. I'm surprised Google encourages syncing the codes to the cloud... kind of defeats the purpose. I sync my TOTP between devices using an encrypted backup, even if someone got that file they could not use the codes. FIDO2 would go a long way to help with this issue. There is no code to share over the phone. FIDO2 can also detect the domain making th…

On the otherhand having your device die means without cloud backup you either lose access or whoever was relying on that 2FA needs to fall back on something else to authenticate you.

After all if I can bypass 2FA with my email whether 2FA is backed up to the cloud doesn't matter from a security standpoint.

Certainly I would agree with the assertion that opting out for providers of codes would be nice. Even if it is an auto populated checkbox based on the QR code.

Re: When MFA isn't MFA, or how we got phished

#33
post #22

Very sophisticated attack, I would bet most people would fall for this. I'm surprised Google encourages syncing the codes to the cloud... kind of defeats the purpose. I sync my TOTP between devices using an encrypted backup, even if someone got that file they could not use the codes. FIDO2 would go a long way to help with this issue. There is no code to share over the phone. FIDO2 can also detect the domain making th…

[deleted]

Re: When MFA isn't MFA, or how we got phished

#34
post #8

Earlier quoted context omitted.

They mean they are syncing the private key used to generate the tokens on demand.

Do all these 2FA apps - like say Microsoft Authenticator - have these hidden/not-so-hidden private keys? From other posts it sounds like you can view the token and write it down... MA doesn't have that, I don't think.

Answering myself again, yeah, they all seem to have this private key hidden away somewhere. Didn't know that.

https://frontegg.com/blog/authentication-apps#How-Do-Authent...?

Re: When MFA isn't MFA, or how we got phished

#35
post #6

I don't understand: Why on earth does google want to sync MFA tokens? They're one-time use, aren't they? Or... feh, I can't even fathom

For me the question is "who the fsck uses Google Authenticator to store all their tokens, both company and personal?"

Google Authenticator was I believe the first available TOTP app, and is by far the most popular. It used to be open source and have no connection to your Google account. Many people installed it years ago when they first set up MFA, and have just been adding stuff to it ever since because it's easy and it works. Even for technical users who understand how TOTP works, there is no obvious reason it appears unsafe to put all your tokens in the app (until you read this article).

Look at the MFA help page for any website you use. One of the first sentences is probably something like "First you'll need to install a TOTP app on your phone, such as Google Authenticator or Authy..."

It really did used to be the best option. For example, see this comment from 10 years ago when Authy first launched:

> The Google Authenticator app is great. I recently got (TOTP) 2-factor auth for an IRC bot going with Google Authenticator; took about 5 minutes to code it up and set it up. It doesn't use any sort of 3rd party service, just the application running locally on my phone. TOTP/HOTP is dead simple and, with the open source Google Authenticator app, great for the end user.

- https://news.ycombinator.com/item?id=6137051

Re: When MFA isn't MFA, or how we got phished

#36
Are the claims of deepfake and intimate knowledge of procedures based of the sole testimony of the employee who oopsed terribly? This is a novelisation of an events

Retool needs to revise the basic security posture. There is no point in complicated technology if the warden just gives the key away.

Re: When MFA isn't MFA, or how we got phished

#37

To deepfake the voice of an actual employee, they would need enough recorded content of that employee's voice... and I would think someone doing admin things on their platform isn't also in DevRel with a lot of their voice uploaded online for anyone to use. So it smells like someone with close physical proximity to the company would be involved.

One possibility would be to just call the employee and record their voice. One could pretend to be a headhunter.

Re: When MFA isn't MFA, or how we got phished

#38
post #22

Very sophisticated attack, I would bet most people would fall for this. I'm surprised Google encourages syncing the codes to the cloud... kind of defeats the purpose. I sync my TOTP between devices using an encrypted backup, even if someone got that file they could not use the codes. FIDO2 would go a long way to help with this issue. There is no code to share over the phone. FIDO2 can also detect the domain making th…

> Very sophisticated attack, I would bet most people would fall for this.

No. If you think people at your company would fall for this, then IMO you have bad security training. The simple mantra of "Hang up, lookup, call back" (https://krebsonsecurity.com/2020/04/when-in-doubt-hang-up-lo...) would have prevented this.

Literally like 99% of social engineering attacks would be prevented this way. Seriously, make a little "hang up, look up, call back" jingle for your company. Test it frequently with phishing tests. It is possible in my opinion to make this an ingrained part of your corporate culture.

Agree that things like security keys should be in use (and given Retool's business I'm pretty shocked that they weren't), but there are other places that the "hang up, look up, call back" mantra is important, e.g. in other cases where finance people have been tricked into sending wires to fraudsters.

Re: When MFA isn't MFA, or how we got phished

#39
post #2

>The caller claimed to be one of the members of the IT team, and deepfaked our employee’s actual voice. The voice was familiar with the floor plan of the office, coworkers, and internal processes of the company. Wow that is quite sophisticated.

Sophisticated enough that I’d just suspect the employee unless there was additional proof.

Re: When MFA isn't MFA, or how we got phished

#40
post #22

Very sophisticated attack, I would bet most people would fall for this. I'm surprised Google encourages syncing the codes to the cloud... kind of defeats the purpose. I sync my TOTP between devices using an encrypted backup, even if someone got that file they could not use the codes. FIDO2 would go a long way to help with this issue. There is no code to share over the phone. FIDO2 can also detect the domain making th…

Sophisticated... ok

I mean it's a great reason to use U2F / Webauthn second factor that cannot be entered into a dodgy site

https://rakkhi.substack.com/p/how-to-make-phishing-impossibl...

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