Usually my (not too many :( ) posts are written for a technical audience (not too big :( ). This time, given the fact October is Cyber Security Month I will try to put some effort to try to explain how you can keep yourself away from annoyances. Well the rule of thumb is actually extremely simple and can be resumed with a simple sentence:
Beware what you click
Let me repeate it: "beware what you click" :)
Just following this simple rule you can avoid 90% of scam/viruses and phishing attacks.
But lets do a step back. Assuming you know already what is a computer's virus let me explain what is a phishing attack. Phishing scam uses legitimate-looking websites to trick a victim into sharing their username, password or other sensitive information. Pishers will design their sites to look exactly like e.g. the website of your mail provider, your bank, credit card issuer, or another financial institution. The hope is that you won't realize you are on the wrong site, and just punch your password like you normally would. Then, they use it to log into your accounts and e.g. transfer out your money.
So here some advice for you:
- Look carefully at a website before giving any information (specially sensitive data)
- Especially look out for slightly misspelled words
- If something looks even a little fishy, delete the mail and close the site ASAP
- Create bookmarks in your browser for commonly used sites (e.g. mail, bank, etc)
- But overall
Beware what you click
Non GEEK can STOP here :) Now let me show some example of phishing based on an open redirect I found on Google-Github OAuth integration :) This is a variant of the 'Lassie Come Home' OAuth attack I previously talked about. In https://console.developers.
google.com/project is possible to connect a project with Github.
So far so good :) The problem is that the Google's OAuth client id
registered in github (namely fde1c8c8834c1b0adcc8) has a registered
redirect_uri that is too open (namely https://console.developers. google.com/). This is because the same OAuth client id is used for every Google
project to connect with github. For example project APPS_A when
connects to Github will end up having this request to the github
and APPS_B will have
Note that the same client_id is used in both requests. This is possible because as said above the registered redirect uri is https://console.developers.
So what an attacker needs to do is to upload an html file in the Google Cloud Storage Bucket and apply some open permission in order to be read by anyone (or by at least by the victim).
The html file will have a fixed uri of https://console.developers.
So now is possible to forge the initial OAuth call like this:
Mind that test.html is controlled by the attacker.
To recap the attack looks like this:
- the attacker forge an url like https://github.com/login/oauth/authorize?client_id=fde1c8c8834c1b0adcc8&redirect_uri=https://console.developers.google.com/m/cloudstorage/b/augmented-tract-3923rewrew233.appspot.com/o/aa/test.html&response_type=code&scope=repo&state=NtMfd5ccxz-a6GtwuqcQiv1L9U
- the victim clicks the link
- this will redirect to https://console.developers.google.com/m/cloudstorage/b/augmented-tract-3923rewrew233.appspot.com/o/aa/test.html?code=ccd04786b8113318c3d7&state=NtMfd5ccxz-a6GtwuqcQiv1L9Uc-
As a consequence Google decided to tighten the redirect_uri in github (now is https://console.developers.
Final note, (unlikely for me) but good for Google:
google.com/m/cloudstorage/b/ augmented-tract-3923rewrew233. appspot.com/o/aa/test.html? code=ccd04786b8113318c3d7& state=NtMfd5ccxz- a6GtwuqcQiv1L9Uc doesn't transfer the parameters over to the final **.googleusercontent.com URL
- And the 'code' parameter it's also not available in the HTTP referrer.