End
of Last Year (2015) we witness Ransomware on the rise. The attack is when
Cybercriminals encrypt data on a victim’s computer and then demands a fee for
unlocking it.
Most
security experts agree that it is almost impossible to recover data that might
have been encrypted in a ransomware attack without access to the decryption
keys, or to a backup copy of the affected data. Therefore, the focus has to be
on prevention.
Early
this Month (February, 2016) A significant number of websites that run on the
WordPress content management system appear to have been compromised so that
they infect site visitors' computers with ransomware and other malware.
The
attacks affect machines that are running versions of Adobe Flash, Adobe Reader,
Microsoft Silverlight, and Internet Explorer that are not up to date on
patches.
Initially,
Ransomware started off mainly as a consumer problem but increasingly is hitting
businesses and government entities as well. Indeed, recovering data encrypted
by a ransomware attack is next to impossible, so prevention offers the better
approach.
The
trend has significantly heightened the need for organizations to have proactive
measures in place for blocking the threat and for mitigating damage to the
extent possible.
“[Ransomware]
is evil because if implemented correctly by the attackers … it is very
difficult to recover the data on the machine,” says Engin Kirda, co-founder and
chief architect at security vendor Lastline. “The key difference of this type
of malware compared to traditional malware is that you often know that you have
been infected because the malware tells you this."
Having
a robust data backup process can go a long way in blunting the threat posed by
ransomware. In fact, it is often the only way to recover data if you are
unwilling to pay the ransom demanded by an extortionist. But there are other
measures that organizations can take as well, including the following:-
Authenticate In-Bound Email: Email is a commonly
used method to distribute ransomware. Attackers target victims with cleverly
spoofed emails that appear to originate from someone the victim knows. The
emails have malicious attachments which when opened results in the ransomware
being downloaded on the victim’s system.
One
of the most effective ways for an organization to blunt this threat is to
validate the origin of an email before it is delivered to the intended
recipient, says Craig Spiezle, executive director and president of the Online
Trust Alliance (OTA).
Implementing
sender identity technologies like Sender Policy Framework (SPF), Domain Message
Authentication Reporting and Conformance (DMARC), and DomainKeys Identified
Mail (DKIM) can all protect organizations against spear phishing, business
email compromise, and other threats posed by spoofed email, Spiezle says. They
work by validating the IP address and domain of the server from which an email
originates.
“Unfortunately,
most corporations are not authenticating inbound mail,” Spiezle says. And when
they do, the policies are not strong enough. For example, emails that fail
authentication tests are often simply quarantined or sent to a junk
folder. Instead, “corporations that have
sensitive information should have a reject policy for emails that fail,”
authentication tests, he says.
Protect Your Email Servers: Sender
authentication can mitigate the risk of ransomware being delivered via email.
But that alone is not sufficient, says Craig Young, security researcher at
Tripwire.
If
you haven’t done so already, protect mail servers by scanning all stored,
incoming, and outgoing mail. Such scanning can help organizations detect
threats that might have evaded perimeter defenses or infiltrated the network
via compromised systems and internal email. Numerous tools are available for
scanning email servers for security threats. Take advantage of them, he says.
“Email
authentication is a good measure to have,” Young says. “But there’s always a
chance that a legitimate email server is used to send out spam emails,” and
other malware, he says.
Add Ad Blocking: In
addition to emails, attackers often distribute ransomware through malicious
advertisements served up to users when they visit certain sites. Advertisements
allow attackers to target victims based on their browsing habits, location,
demographic information, device characteristics, and other criteria. Ransomware
served up via watering-hole attacks often tend to be more dangerous than random
attacks because they are targeted at victims which the attackers know have the
capability to pay up.
Blocking
ads from being delivered on user systems or preventing users from accessing
certain sites can diminish this risk somewhat, Spiezle says. Organizations that
want to accommodate unrestricted access to the Internet for employees might
consider implementing a separate network for them to do so, he says, pointing
to one government contractor that has taken this approach.
Monitor File Activity:
With ransomware, an attack against an individual can quickly escalate into an
attack against the enterprise, says Amichai Shulman, chief technology officer
at Imperva. Many ransomware tools have the ability to encrypt not just the hard
drive of a system, but also any shared files.
In
fact, rapid file overwriting is one of the clearest markers of ransomware on
your network, he says. So using a tool to monitor file activity is a good idea,
says Shulman, whose company sells an activity-monitoring tool.
“If
you are constantly monitoring access to file servers, there are very
distinctive patterns that you can look for in order to detect ransomware,” on
an endpoint, he says.
Such
early detection can help organizations contain the damage that a ransomware
tool can wreak, he says. “The advantage is that you can go quickly into
quarantine mode for the infected machine and make sure it doesn’t connect to
any other file server,” in the enterprise.
Keep Your Response Plan Handy: Time
is critical for an organization faced with a ransomware deadline. Online extortionists
typically give organizations a very specific time limit within which to pay -- After
which they sharply increase the ransom amount.
Attackers
have gotten increasingly better at knowing what an organization can afford and
knowing exactly when to strike, Spiezle says. They deliberately don’t give
enough time for an organization to figure out if it can try and unlock the data
without paying any ransom.
So
it is important to have a plan in place describing what needs to happen in the
event of a ransomware attack. Do inventories of your critical data assets, know
where it is located, and evaluate that impact of any loss or unavailability of
that data.
“One of the worst things is the chaos that
ensues during an incident like this. Emotions run high, people don’t have the
answers and they are scrambling,” to respond. he says. “The last thing you want
is to be doing a Google search for local forensics experts at 2am on a Saturday
morning.”
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