At the beginning of May, Google released eight new top-level domains (TLDs)—the suffixes at the end of URLs, like “.com” or “.uk.” These little addendums were developed decades ago to expand and organize URLs, and over the years, the nonprofit Internet Corporation for Assigned Names and Numbers (ICANN) has loosened restrictions on TLDs so organizations like Google can bid to sell access to more of them. But while Google’s announcement included light-hearted offerings like “.dad” and “.nexus,” it also debuted a pair of TLDs that are uniquely poised to invite phishing and other types of online scamming: “.zip” and “.mov”.
The two stand out because they are also common file extension names. The former, .zip, is ubiquitous for data compression, while .mov is a video format developed by Apple. The concern, which is already starting to play out, is that URLs that look like file names will open up even more possibilities for digital scams like phishing that trick web users into clicking on malicious links that are masquerading as something legitimate. And the two domains could also expand the problem of programs mistakenly recognizing file names as URLs and automatically adding links to the file names. With this in mind, scammers could strategically buy .zip and .mov URLs that are also common file names—think, springbreak23.mov—so online references to a file with that name could automatically link to a malicious website.
“Attackers will use whatever they can to get inside an organization,” says Ronnie Tokazowski, a longtime phishing researcher and principal threat adviser at the cybersecurity firm Cofense. “Man, this all goes back a long time now. Nothing has changed.”
Researchers have already started seeing malicious actors buying up strategic .zip URLs and begin testing them in phishing campaigns. But reactions are mixed on how much of a negative impact .zip and .mov domains will have when scams that prey on URL confusion are already an inveterate threat. Additionally, proxies and other traffic management tools already deploy anti-phishing protections to cut down on the risks if users mis-click—and .zip and .mov will simply be incorporated into those defenses.
“The risk of confusion between domain names and file names is not a new one. For example, 3M’s Command products use the domain name command.com, which is also an important program on MS DOS and early versions of Windows,” Google told WIRED in a statement. “Applications have mitigations for this (such as Google Safe Browsing), and these mitigations will hold true for TLD’s such as .zip.” The company added that Google Registry already includes mechanisms to suspend or remove malicious domains across all of the company’s top-level domains. “We will continue to monitor the usage of .zip and other TLDs, and if new threats emerge we will take appropriate action to protect users,” the company said.
Offering more TLDs broadens the number of URLs that are available to people. This means you have more choices and don’t necessarily have to pay a premium to buy the site name you want from an existing owner or speculator who bought up a bunch of historic URLs. And some in the security community feel that, given the already extensive risk of phishing attacks, additions like .zip and .mov add negligible additional danger.
“I don’t agree with the assertion that the new TLDs will increase the effectiveness of phishing in any meaningful way—primarily because people are already so easily fooled by URLs,” says security researcher Troy Hunt, who runs the breach-tracking service HaveIBeenPwned. “Not only can we, myself included, not tell the difference between so many ambiguous characters, we also usually have no idea what the correct URL is for many services. I bet you this all blows over before you know it with no incidents of consequence.”
Some researchers feel strongly, though, that a company like Google, which invests so much in anti-scam and anti-phishing work, could have simply opted not to offer these particular TLDs. Even if other top-level domains exist that are also file extensions, they argue that the world doesn’t need more of these overlaps.
“Nobody said this was new. In fact, half the issue is that it’s not new,” says security researcher Marcus Hutchins. “We’ve had this issue in the past, and Google has just gone and caused the same problem again. It really seems like they created a big usability and security issue for downstream providers to clean up, all for no reason other than a low-effort money grab.”
Lily Hay Newman