Maybe double-check that HMRC email? UK taxman remains a fave among the phisherfolk

July 16, 2019 TH Author

The UK’s National Cyber Security Centre (NCSC) has had another busy year trying to disrupt cybercrime.

The government agency today reported that in the past 12 months, it stopped 140,000 phishing attacks and took down more than 190,000 fraudulent sites and services.

Impersonating the taxman remained phishers’ favourite pastime, with 6,752 attacks involving HMRC stopped in 2018 – more than any other public sector department.

The second favourite was the government portal (Gov.uk), followed by the (now defunct) Government Gateway identification service, DVLA and the TV Licensing service. The top 10 was rounded up by the BBC, Student Loans Company and three unnamed universities.

The report called this a marked improvement on 2017: “The number of groups we’ve taken down targeting HMRC has fallen by 46 per cent when comparing 2017 and 2018.

“As a proof of principle, it seems that we can affect the return on investment for criminals and demotivate them from attacking things we care about.”

The NCSC also discovered that at least 318 public sector networks and 168 unique organisations were still using Windows XP – the OS that hasn’t seen a single security patch since the middle of 2014.

These and other public sector close calls were disclosed in a 84-page sequel to last year’s report, imaginatively titled “Active Cyber Defence – The Second Year” [PDF].

The Active Cyber Defence programme was launched in 2017 to “protect the majority of people in the UK from the majority of the harm, caused by the majority of the attacks, for the majority of the time”.

In reality, it appears that its primary purpose is to protect the government against reputational damage that manifests when its websites and services are implicated in cybercrime, and safeguard public sector employees against fraud.

The responsibility for these tasks was laid on the shoulders of NCSC, a relatively new government body established under the auspices of the Government Communications Headquarters (GCHQ) in 2016.

Its duties include using automated tools to discover illegitimate websites, then informing ISPs and “asking, very nicely, if they wouldn’t mind awfully removing it”. The agency doesn’t serve legal papers on the hosters because of the length of the process.

Not everyone complies with these voluntary requests fast enough: the agency singled out French hoster OVH and American giant GoDaddy as increasingly tardy. “We are in discussions with GoDaddy to help optimise the interaction between our takedown processes,” the agency said.

The report also noted that NCSC prevented 1.4 million employees in the public sector from visiting malicious sites. As part of the effort, the agency used something called PDNS, a protected DNS service that refuses to query domains previously found to be engaged in suspicious activity.

This system was able to block 57.4 million malicious queries in 12 months. These included 13,800 queries for at least 20 named (i.e. famous) botnet C&C systems, including Betabot, Graybird, Katrina, Lokibot, StealRat and Godzilla.

“The PDNS service has proven its value already, providing a real protective eﬀect at scale to the subscribed customers. In the next year of service, we are intending to retender the service and look to onboard more public sector customers,” the report said.

Surprisingly, a few queries identified by PDNS were related to the infamous Conficker worm. “Yes, Conficker,” the incredulous authors wrote in a footnote. “The same one from 2008. It’s still active somewhere in public sector.”

The Second Year also detailed a sophisticated phishing operation that involved emails sent from a fake gov.uk address, purporting to be from an organisation in the aviation sector. The campaign took place in August 2018, involving 200,000 emails in an attempt at advance fee fraud.

The NCSC discovered and stopped the attack by using Synthetic DMARC (Domain-based Message Authentication, Reporting and Conformance), a system developed by the agency to analyse and vet non-existent subdomains like theregister.gov.uk.

“Be clear though: this remains an evil hacky kludge and we need a better way to express policy ownership in domain hierarchies,” the report admitted.

“The problem with DMARC is that it only protects against a small fraction of the threats on email,” said Tim Sadler, CEO at cybersecurity firm Tessian. “Businesses and government agencies should be aware that a high percentage of emails employees receive are still not DMARC authenticated. This means that while their own domain may be protected from direct impersonation, their employees remain vulnerable to direct impersonation of their external contacts.”

And finally, the NCSC detailed all the new initiatives it started in 2019, the results of which will be published in 2020. These include removal of web shells in the UK, notiﬁcation of “non-consensual” crypto-mining on UK sites, managing advance fee fraud related to the UK legal system, and compromise of UK-based Magento shopping carts with credit card skimming code. ®

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