Automatic text replacement let users spoof URLs ending in x, like netflix.com.

Automatic text replacement let users spoof URLs ending in x, like netflix.com.

Elon Musk’s clumsy brand shift from Twitter to X caused a potentially big problem this week when the social network started automatically changing “twitter.com” to “x.com” in links. The automatic text replacement reportedly applied to any URL ending in “twitter.com” even if it wasn’t actually a twitter.com link.

The change apparently went live on X’s app for iOS, but not on the web version. It seems to have been a problem for a day or two before the company fixed the automatic text replacement so that it wouldn’t affect non-Twitter.com domains.

Security reporter Brian Krebs called the move “a gift to phishers” in an article yesterday. It was a phishing risk because scammers could register a domain name like “netflitwitter.com,” which would appear as “netflix.com” in posts on X, but clicking the link would take a user to netflitwitter.com.

“A search at DomainTools.com shows at least 60 domain names have been registered over the past two days for domains ending in ‘twitter.com,’ although research so far shows the majority of these domains have been registered ‘defensively’ by private individuals to prevent the domains from being purchased by scammers,” Krebs wrote.

    • @zeppoEnglish
      14•7 months ago

      Are you serious?

      As of April 8, 2024, the iOS Twitter (now X) client automatically replaces the text “twitter.com” in posts with “x.com” as part of its functionality. Therefore, for example, a URL that appears to be “netflix.com” will actually redirect to “netflitwitter.com” when clicked.

      As another X user (@Arcticstar0) pointed out, “the actual link is unchanged. It’s just the text placeholder that appears different. So the link goes to a different url than it appears.”

      It could work the way you’re describing with the same effect, but that’s not what’s being described.

      • @[email protected]
        3•7 months ago

        Quoting your quote, now with emphasis:

        a URL that appears to be “netflix.com” will actually redirect to “netflitwitter.com” when clicked

        So, as I said, the link text you see appears unchanged, but where it goes is changed. That’s why it’s a phishing concern.

          • @[email protected]
            -1•7 months ago

            No. If the link was left pristine, phishing would be impossible, because the original links we’re discussing went to genuine sites and the displayed link would be obviously garbage.

            The whole problem is that people are linking to netflitwitter with a display of netflitwitter, then the regex changes the link target, so you see the original, sane address, click on it, and get deceived into going to a target the regex fabricated.

            • @zeppoEnglish
              3•7 months ago

              That COULD be what happened, and it would have a similar effect, but it wasn’t what happened. If you read information about this that becomes apparent. They didn’t change the link target, they changed the link text only.

              Someone registers spacetwitter.com and sets up an adversarial site. They then make an “X” post mentioning spacetwitter.com. The app creates a link to spacetwitter.com but changes the text to say spacex.com.

              Please read this: https://krebsonsecurity.com/2024/04/twitters-clumsy-pivot-to-x-com-is-a-gift-to-phishers/

              On April 9, Twitter/X began automatically modifying links that mention “twitter.com” to read “x.com” instead. But over the past 48 hours, dozens of new domain names have been registered that demonstrate how this change could be used to craft convincing phishing links — such as fedetwitter[.]com, which until very recently rendered as fedex.com in tweets.

              Notice how it says modifying links that mention “twitter.com” to read “x.com” instead.