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Three Tough Questions You Must Ask About HTTPS to Avoid Cyber Attacks

Preventing your organization from being the victim of an inevitable cyber-attack is paramount so it is important for us to kick off this blog with an important risk question.

Do you know whether or not your organization‘s firewall is inspecting HTTPS traffic traversing its networks?

I have polled this question on numerous webinars I have conducted over the past year. The results consistently showed the majority of organizations have yet to perform HTTPS inspection as part of their defense strategy. With HTTPS on the rise, accounting for nearly two-third of your organization’s internet traffic today, hackers have expanded their craft to use the protocol to obfuscate their attacks and malware from security systems. Your timely response to this new threat could mean the difference between experiencing a material breach versus successfully averting one. Of course, the latter would be desirable. So, should you have the slightest doubt about your organization’s security posture to deal with encrypted threats, I want you to immediately pause and resume reading this post after you have spoken to your IT security leaders. I’d like you to raise your concerns about the potential millions of intrusions and tens of thousands of malware attacks launched against your organization each and every hour – many of which are likely new versions of ransomware delivered inside of HTTPS sessions. If the firewall is not inspecting this traffic, it would not have the ability to understand what is inside that traffic – whether a file is benign or malicious, credit cards being stolen or financial and health records were being shared with an external system. I hope you return to this blog with a sigh of relief that your organization is not among the majority of respondents that do not.

You got the good news that your organization is inspecting HTTPS traffic. The next logical question is:

“Has your organization experienced frequent network service disruptions or downtime as a result of a total collapse of your firewall performance when inspecting HTTPS traffic?”

Inspecting encrypted traffic is not without its set of big challenges. There are two key components of HTTPS inspection that severely impact firewall performance – establishing a secure connection and decrypting and later re-encrypting packets for secured data exchange. Unlike inspecting internet traffic in plain text, encrypted traffic introduces six additional compute processes that must occur before data is sent back and forth between a client’s browser and the web server over an HTTPS connection. Each process is highly complex and compute-intensive. Most firewall designs today don’t provide the right combination of inspection technology and hardware processing power to handle HTTPS traffic efficiently. They often collapses under the load and subsequently disrupt business-critical operations. According to NSS Labs, the performance penalty on a firewall when HTTPS inspection is enabled can be as high as 81 percent. In other words, your firewall performance is degraded to a level that it is no longer usable.

This leads us to the final and most important question:

“How can you scale firewall protection to prevent performance degradation, lag and latency of your network when inspecting HTTPS traffic?”

The right answer begins with the right inspection architecture as the foundation. Most modern firewalls today have deep packet inspection (DPI) capability claiming to solve many of the above security and performance challenges. However, not all firewalls perform equally or as advertised in the real world. In fact, many of them have inherent design inefficiencies that reduce their ability to handle today’s massive shift towards an all-encrypted Internet. You have one of two choices when it comes to inspection technology. These are Reassembly-Free Deep Packet Inspection (RFDPI) and Packet Assembly-based. Each uses different inspection method to scan and analyze data packets as they pass the firewall. You will quickly discover the performance of most firewalls will collapse under heavy HTTPS load. To avoid a post-deployment surprise, my recommendation is to do your due diligence. Thoroughly qualify and measure all firewalls under consideration and select one that meets both your desire level of performance and security effectiveness without hidden limitations. These are fundamental metrics that you want to heavily scrutinize when selecting a firewall to perform HTTPS inspection. Establishing the right firewall foundation will give you the agility to scale your security layer and solve the performance burden of inspecting HTTPS traffic inside your data center operations.

Uncovering evasive threats hiding inside encrypted network traffic is central to the success of your network defense. For more detail information, read our Executive Brief titled, “The Dark Side of Encryption – Why your network security needs to decrypt traffic to stop hidden threats.”

Ransomware Can Cost You Millions; Is Your Network Secure?

Recently it was reported that in April 2016 an employee at Michigan-based utility company BWL opened an email and clicked on a malicious attachment laden with ransomware. The result? It shut down accounting and email systems as well as phone lines, which lead to a costly and laborious week of recovery.

The cost? $2.4 million.

Let That Sink in for a Second.

In a separate case, the $800K ransom heaped upon the City of Detroit by hackers in 2014 served as an anecdotal warning of the potential for this class of malware.  But in the BWL case, only $25K was actually paid to the attackers with 99 percent of the costs related to technology upgrades and people responding to the attack.  To save you on the mental math, the actual ransom was about 1 percent of the total costs. This could be the setting for a modern proverb based on For Want of a Nail.  The silver lining is the improvement of the utility’s security and the overhaul of its IT communication policy.

What Does This Teach Us?

For all the talk of cost of the ransoms levied upon victims, the impact is much greater.  In this example, it cost the organization in lost business, impact to the customer experience, and even more on the human resources side. It also serves as a poster child for ineffective spam management and phishing prevention.  Ultimately this problem is happening around the world and despite the best intentions at stopping ransomware, it still persists.

What Do You Do If You Are Hit?

First of all, don’t panic.  By default, you need to consider not paying the ransom and find a way to restore systems and data without giving in.  Otherwise, it’s like feeding a feral cat; hackers will be found on your doorstep the next day. Simultaneously, you need to restore systems, discover the point of origin, and stop follow-on attacks.  This is where the backup and security stories combine.

In the case of BWL, it took a lot of human resources and two weeks’ worth of time, most likely because the utility was not prepared for this type of attack.  In your case, find the point of origin and restore a backup from before that event.

But What About Stopping Follow on Attacks?

Before the Firewall

I would like to say that out there is a single solution that will solve this but that isn’t completely true.  In short, the answer is education, security and backup.  The first thing to do is to build the human firewall; teach your employees not to click on attachments or links in suspicious emails, especially if you deal with payments.  This is just the first step; a recent Barkly study stated that in their data set, 33 percent of ransomware victims had already undergone security awareness training.

Additionally, think long and hard before hanging “blamable” employees out to dry.  It may be shortsighted to fire or reprimand an employee for unleashing malware unless they were clearly going outside the boundaries of ethical/lawful internet usage (e.g. browsing adult sites, downloading pirated material, etc.). In many cases, ransomware comes through a cleverly crafted phishing email, and given the fact that BWL’s accounting and email systems were taken offline, I’m assuming an accounts payable person opened an attachment from a hacker with an “unpaid invoice.”

When it comes to technology, you need to have a multi-layered approach to eliminate malware as it approaches your environment.  Look at the image below and you can see how SonicWall stops ransomware via web and device traffic.  In the case of watering hole attacks (e.g., downloading malware from a website), SonicWall Content Filtering Service (CFS) blocks millions of known malicious sites to help remove major sources of pulled malware from the equations.  After this, deploy SSL/TLS decryption to help you see all traffic.  Four years ago, the percentage of traffic being encrypted was very low by comparison today.  Forget the advertised malware-catch-rate of a vendor’s firewall and sandbox; if they can’t inspect 50 percent of traffic, it’s like locking and guarding the front door while leaving the backdoor open.

The Firewall and Capture ATP

If you are using SSL decryption, now all of the traffic coming into your organization can be viewed by your firewall.  Hopefully, this is a modern device that can inspect every byte of every packet to look for threats and approve files quickly.  In the case of device traffic, it hits the firewall and should be directed to your mobile access or VPN appliance to decrypt data and control access to only approved device IDs.  This traffic should be sent back to the firewall to begin its journey along with web traffic, through a gauntlet of rapid security measures.

The firewall and VPN appliances are the hardware portion of the equation with the firewall being the keystone of it all.  Firewalls are defined by their services because they do a lot of the work at removing malware from your internet traffic.  Traditionally, gateway security and anti-virus follow the firewall looking for malware based on a set of signatures; meaning this is how you eliminate known malware.  Point in case, SonicWall eliminated nearly 90 million ransomware attempts in the month of May 2016 using this same technology. Malware is used over and over again and may be seen thousands of times within an hour of its release.  Leveraging a cloud-based signature engine will enable you to have better protection against newer threats.

After going through gateway security, many networks leverage a network sandbox, which is an isolated environment to run suspicious code to see what it does.  This is where a lot of unknown malware is discovered and stopped.  Network sandboxes have been around for a few years now but hackers have found ways to design malicious code to evade their detection, which is why some analysts recommend leveraging multiple sandboxes from multiple vendors to see as much as you can.  I recommend using SonicWall Capture Advanced Threat Protection (ATP) multi-engine sandbox that combines virtualized sandboxing, hypervisor level analysis and full-system emulation to help see what potential malware wants to do from the application, to the OS, to the software running on the hardware.  Since ransomware variants are redeveloped throughout their lifecycle, it is important for sandboxes to create cloud-based sharable hashes for every version possible to block follow-on attacks and shorten the lifespan of ransomware. Through this process a lot of malware is scrubbed out from the point of origin to the server.

Endpoints and Backup

Although this setup is highly effective, you will need to maintain a healthy endpoint protection strategy.  Anti-virus for endpoints is still important, but today it is easier to manage than before.  Leverage an enforced anti-virus technology that doesn’t allow employees to access the internet through a web browser without up-to-date endpoint protection.  In these cases, employees are directed to a download page to update their anti-virus software before they can go and click on that suspicious link in email.

Lastly: back up, back up, and back up some more.  Ransomware exists because organizations keep paying the attackers for their data.  If a ransomware attack evades the common sense of people and the fortifications of your security infrastructure, you can simply wipe the device or server clean and refresh from your back up.

Download our solution brief: How to protect against ransomware.