SpamHaus ranks most-botted TLDs and registrars

Namecheap and Uniregistry have emerged as two of the most-abused domain name companies, using statistics on botnet command and control centers released by SpamHaus this week.

SpamHaus data shows that over a quarter of all botnet C&Cs found during the year were using NameCheap as their registrar.

It also shows that almost 1% of domains registered in Uniregistry’s .click are used as C&Cs.

The spam-fighting outfit said it discovered “almost 50,000” domains in 2017 that were registered for the purpose of controlling botnets.

Comparable data for 2016 was not published a year ago, but if you go back a few years, SpamHaus reported that there were just 3,793 such domains in 2014.

Neither number includes compromised domains or free subdomains.

The TLD with the most botnet abuse was of course .com, with 14,218 domains used as C&C servers. It was followed by Directi’s .pw (8,587) and Afilias’ .info (3,707).

When taking into account the relative size of the TLDs, SpamHaus fingered Russian ccTLD .ru as the “most heavily abused” TLD, but its numbers don’t ring true to me.

With 1,370 botnet controllers and about five and a half million domains, .ru’s abused domains would be around 0.03%.

But if you look at .click, with 1,256 botnet C&Cs and 131,000 domains (as of September), that number is very close to 1%. When it comes to botnets, that’s a high number.

In fact, using SpamHaus numbers and September registry reports of total domains under management, it seems that .work, .space, .website, .top, .pro, .biz, .info, .xyz, .bid and .online all have higher levels of botnet abuse than .ru, though in absolute numbers some have fewer abused domains.

In terms of registrars, Namecheap was the runaway loser, with a whopping 11,878 domains used to control botnets.

While SpamHaus acknowledges that the size of the registrar has a bearing on abuse levels, it’s worth noting that GoDaddy — by far the biggest registrar, but well-staffed with over-zealous abuse guys — does not even feature on the top 20 list here.

SpamHaus wrote:

While the total numbers of botnet domains at the registrar might appear large, the registrar does not necessarily support cybercriminals. Registrars simply can’t detect all fraudulent registrations or registrations of domains for criminal use before those domains go live. The “life span” of criminal domains on legitimate, well-run, registrars tends to be quite short.

However, other much smaller registrars that you might never have heard of (like Shinjiru or WebNic) appear on this same list. Several of these registrars have an extremely high proportion of cybercrime domains registered through them. Like ISPs with high numbers of botnet controllers, these registrars usually have no or limited abuse staff, poor abuse detection processes, and some either do not or cannot accept takedown requests except by a legal order from the local government or a local court.

The SpamHaus report, which you can read here, concludes with a call for registries and registrars to take more action to shut down repeat offenders, saying it is “embarrassing” that some registrars allow perpetrators to register domains for abuse over and over and over again.

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Tagged: .click, .ru, abuse, botnets, namecheap, spamhaus, uniregistry