By Michael Cooney
Few things can strike fear into the heart of the IT department like an
attack on a company's Domain Name System servers. That may explain why
companies are spending so much time to deploy myriad, complex security
measures to keep their DNS protected from malicious attackers.
A study released Wednesday of 465 IT and business professionals says
despite the Sisyphean efforts, many companies remain vulnerable. More
than half the respondents reported having fallen victim to some form of
malware attack. More than one-third had been hit by a denial-of-service
(DoS) attack, and more than 44% had experienced a pharming or
cache-poisoning attack. External and internal DNS servers were equally
vulnerable: Both types succumbed to attacks with roughly the same
frequency, according to the study by Mazerov Research and Consulting.
A DNS server compromised by a hacker could be used to funnel Web surfers
to all sorts of phishing attacks and malicious Web sites, and in some
cases even could cause havoc with directory services and e-mail, said
Paul Mockapetris, the father of the DNS technology, in a Network World
story earlier this year. Once you control the DNS server, you have
license to do phishing and pharming attacks and mislead all the users of
that DNS server, said Mockapetris, who in 1983 proposed the DNS
architecture and is acknowledged, along with the late Jon Postel, as the
According to the Mazerov study, DoS attacks are prevalent among the
respondents, with only 16% never having experienced one, although more
than 10% said they often or frequently receive DoS attacks to their
network. What also is interesting is that, while a total of 59% of
respondents rarely or never experience DoS attacks, a surprisingly high
41% experience them. The study found that the top forms of DNS attack
are malware (worms, viruses, Trojans and so forth), 68%; denial of
service, 48%; cache poisoning, 36%; and pharming, 23%.
The patching game seems to be the method of choice for protecting DNS.
Three-quarters of all respondents devote valuable resources to patching
their operating systems continuously. Others reported having to harden
operating systems; invest in dedicated firewalls; and add DNS
appliances, DoS mitigation services and other network security devices.
On average, respondents typically used at least 3.5 overlapping methods
simultaneously to shore up their DNS security.
The study also looked at how long respondents companies could weather
DNS being taken offline before significant problems occurred, IT
personnel were more sensitive to the issue than those occupying
C-suites. According to the study, C-level executives estimated they
could withstand losing Internet connectivity for slightly more than two
hours (126 minutes), whereas IT managers estimated significant problems
would arise after 105 minutes. Other IT personnel who may be most
directly responsible for maintaining Internet uptime estimated an even
shorter time frame an average of 72 minutes.
Respondents also were asked to assess what the probable impact would be
on the health of their company if they were to experience a loss of
Internet connectivity for a significant period of time. Maybe most
alarming was that 12% of participants claimed they would be extremely or
somewhat likely to go out of business completely, the study said.
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