Late final week [2023-02-16], common website hosting firm GoDaddy filed its obligatory annual 10-Ok report with the US Securities and Exchange Commission (SEC).
Under the sub-heading Operational Risks, GoDaddy revealed that:
In December 2022, an unauthorized third celebration gained entry to and put in malware on our cPanel internet hosting servers. The malware intermittently redirected random buyer web sites to malicious websites. We proceed to analyze the basis explanation for the incident.
URL redirection, also called URL forwarding, is an unexceptionable characteristic of HTTP (the hypertext switch protocol), and is often used for all kinds of causes.
For instance, you may resolve to vary your organization’s most important area identify, however wish to hold all of your outdated hyperlinks alive; your organization may get acquired and must shift its internet content material to the brand new proprietor’s servers; otherwise you may merely wish to take your present web site offline for upkeep, and redirect guests to a brief web site within the meantime.
Another necessary use of URL redirection is to inform guests who arrive at your web site through plain outdated unencrypted HTTP that they need to go to utilizing HTTPS (safe HTTP) as a substitute.
Then, as soon as they’ve reconnected over an encrypted connection, you possibly can embrace a particular header to inform their browser to begin with HTTPS in future, even when they click on on an outdated http://... hyperlink, or mistakenly sort in http://... by hand.
In truth, redirects are so widespread that when you cling round internet builders in any respect, you’ll hear them referring to them by their numeric HTTP codes, in a lot the identical method that the remainder of us speak about “getting a 404” once we attempt to go to a web page that not exists, just because 404 is HTTP’s Not Found error code.
There are literally a number of totally different redirect codes, however the one you’ll most likely hear most often referred to by quantity is a 301 redirect, also called Moved Permanently. That’s when you already know that the outdated URL has been retired and is unlikely ever to reappear as a straight reachable hyperlink. Others embrace 303 and 307 redirects, generally referred to as See Other and Temporary Redirect, used once you count on that the outdated URL will in the end come again into energetic service.
Here are two typical examples of 301-style redirects, as used at Sophos.
The first tells guests utilizing HTTP to reconnect immediately utilizing HTTPS as a substitute, and the second exists in order that we are able to settle for URLs that begin with simply sophos.com by redirecting them to our extra typical internet server identify www.sophos.com.
In every case, the header entry labelled Location: tells the online consumer the place to go subsequent, which browsers usually do robotically:
$ curl -D - --http1.1 http://sophos.com HTTP/1.1 301 Moved Permanently Content-Length: 0 Location: https://sophos.com/ <--reconnect right here (similar place, however utilizing TLS) . . . $ curl -D - --http1.1 https://sophos.com HTTP/1.1 301 Moved Permanently Content-Length: 0 Location: https://www.sophos.com/ <--redirect to our internet server for precise content material Strict-Transport-Security: . . . <--next time, please use HTTPS to begin with . . .
The command line choice -D - above tells the curl program to print out the HTTP headers within the replies, that are what issues right here. Both these replies are easy redirects, which means that they don’t have any content material of their very own to ship again, which they denote with the header entry Content-Length: 0. Note that browsers usually have built-in limits on what number of redirects they’ll comply with from any beginning URL, as a easy precaution in opposition to getting caught up in an endless redirect cycle.
Redirect management thought of dangerous
As you possibly can think about, having insider entry to an organization’s internet redirection settings successfully means that you could hack their internet servers with out modifying the contents of these servers straight.
Instead, you possibly can sneakily redirect these server requests to content material you’ve arrange elsewhere, leaving the server knowledge itself unchanged.
Anyone checking their entry and add logs for proof of unauthorised logins or surprising adjustments to the HTML, CS , PHP and JavaScript information that make up the official content material of their web site…
…will see nothing untoward, as a result of their very own knowledge gained’t even have been touched.
Worse nonetheless, if attackers set off malicious redirects solely from time to time, the subterfuge might be laborious to identify.
That appears to have been what occurred to GoDaddy, provided that the corporate wrote in a assertion by itself web site that:
In early December 2022, we began receiving a small variety of buyer complaints about their web sites being intermittently redirected. Upon receiving these complaints, we investigated and located that the intermittent redirects had been occurring on seemingly random web sites hosted on our cPanel shared internet hosting servers and weren’t simply reproducible by GoDaddy, even on the identical web site.
Tracking down transient takeovers
This is identical kind of downside that cybsersecurity researchers encounter when coping with poisoned web adverts served up by third-party advert servers – what’s recognized ih the jargon as malvertising.
Obviously, malicious content material that seems solely intermittently doesn’t present up each time you go to an affected web site, in order that even simply refreshing a web page that you simply aren’t certain about is more likely to destroy the proof.
You may even completely fairly settle for that what you simply noticed wasn’t an tried assault, however merely a transient error.
This uncertainty and unreproducibility sometimes delays the primary report of the issue, which performs into the fingers of the crooks.
Likewise, researchers who comply with up on reviews of “intermittent malevolence” can’t make sure they’re going to have the ability to seize a duplicate of the dangerous stuff both, even when they know the place to look.
Indeed, when criminals use server-side malware to change the behaviour of internet providers dynamically (making adjustments at run-time, to make use of the jargon time period), they will use a variety of exterior elements to confuse researchers even additional.
For instance, they will change their redirects, and even suppress them fully, primarily based on the time of day, the nation you’re visiting from, whether or not your’re on a laptop computer or a telephone, which browser you’re utilizing…
…and whether or not they assume you’re a cybersecurity researcher or not.
What to do?
Unfortunately, GoDaddy took practically three months to inform the world about this breach, and even now there’s not loads to go on.
Whether you’re an internet consumer who’s visited a GoDaddy-hosted web site since December 2022 (which most likely contains most of us, whether or not we realise it or not), or a web site operator who makes use of GoDaddy as a internet hosting firm…
…we aren’t conscious of any indicators of compromise (IoCs), or “signs of attack”, that you simply might need observed on the time or that we are able to advise you to seek for now.
Worse nonetheless, despite the fact that GoDaddy describes the breach on its web site below the headline Statement on latest web site redirect points, it states in its 10-Ok submitting that this can be a a lot longer-running onslaught than the phrase “recent” appears to indicate:
Based on our investigation, we imagine [that this and other incidents dating back to at least March 2000] are a part of a multi-year marketing campaign by a complicated risk actor group that, amongst different issues, put in malware on our techniques and obtained items of code associated to some providers inside GoDaddy.
As talked about above, GoDaddy has assured the SEC that “we continue to investigate the root cause of the incident”.
Let’s hope that it doesn’t take one other three months for the corporate to inform us what it uncovers in the midst of this investigation, which seems to stretch again three years or extra…