Network Encryption: A Double-edged Sword for Cybersecurity

In 2013, lower than half of all internet visitors was encrypted, in keeping with Google. In the present day, the speed of community encryption stands at 95%.

On the one hand, that is good for safety. The extra issues are encrypted, the more durable it’s for attackers to steal knowledge, listen in on communications, and compromise techniques.

Associated: You’ve Encrypted Your Information within the Cloud, however are Your Keys Protected?

Then again, the identical encryption that can be utilized to guard individuals, knowledge, and techniques can be utilized by cybercriminals and state actors to guard their individuals, knowledge, and techniques.

In line with a report launched by Zscaler final fall, 80% of assaults now use encrypted channels – up from simply 57% the earlier 12 months.

In reality, criminals are forward of enterprises of their use of encryption.

In line with the Ponemon Institute’s 2021 international encryption tendencies survey, 50% of organizations have a consistently-applied encryption technique. One other 37% have a restricted encryption technique, utilized to a restricted variety of functions or knowledge varieties.

Community encryption and privateness

Encrypted visitors is much less more likely to be inspected by safety groups, and makes malicious recordsdata more durable to detect.

In line with a SANS safety operations middle survey launched in October, solely 22% of firms examine all encrypted visitors, whereas 45% do no interception in any respect and 30% have TLS interception applied however do not do something with the knowledge.

The commonest motive for not monitoring visitors? Company considerations about laws and privateness. Nevertheless, not one of the firms who had been inspecting encrypted visitors reported any authorized points.

“There is a mild and a darkish aspect to any know-how you herald to crack encrypted communications,” mentioned Zach Jones, senior director of detection analysis at NTT Utility Safety. “While you crack that open, possibly you possibly can achieve further visibility, however guess what could possibly be in there? PII and delicate data. You’ll be able to create extra issues for your self if you happen to mishandle that delicate knowledge. I’ve seen anecdotes of safety groups going fallacious in the event that they had been logging one thing they shouldn’t have been.”

Defending towards encrypted malicious visitors requires that firms have controls in place on inbound visitors to maintain malware and attackers out, on outbound visitors to stop exfiltration of knowledge, and on inside visitors to stop attackers from transferring laterally by means of networks.

Inspecting inbound visitors

Legacy techniques can simply grow to be bottlenecks, slowing down visitors and impacting staff and prospects.

In the present day, organizations are transferring to cloud-native proxies that examine inbound visitors earlier than it hits company networks, filtering out malicious messages earlier than they will clog the pipes.

In line with a WatchGuard report launched this January, firms that inspected incoming encrypted visitors mentioned that 70% of malware got here in over an encrypted connection.

However although inspection capabilities are constructed into WatchGuard’s Firebox safety product, most prospects do not flip it on, the corporate mentioned. “Having a firewall with out configuring it to examine for zero day malware or configuring to examine encrypted connections doesn’t use the total benefit provided by a firewall and leaves large safety holes in your community perimeter if not mounted.”

In an analogous report launched the earlier quarter, WatchGuard reported that solely 20% of shoppers had been scanning encrypted visitors – whereas 91% of assaults got here in by way of that channel.

For instance, attackers have been encrypting visitors to keep away from detection of Log4Shell assaults, reported risk researchers at ExtraHop.

Mike Manrod, CISO at Grand Canyon Training, mentioned that he confronted simply this subject. The group supplies shared tech companies to Grand Canyon College in Phoenix, Arizona, in addition to different academic establishments – greater than 100,000 customers in complete.

Coping with Log4Shell’s encrypted communications required three ranges of protection, Manrod advised Information Middle Information.

First, there was a cloud-based internet software firewall, which stopped 90% of the assaults, he mentioned, with out creating points with efficiency latency.

“However not all visitors can undergo the cloud WAF,” he added.

So one other 9% of the Log4Shell assaults had been stopped by the sting firewall.

That also leaves a small variety of assaults that received by means of each layers of safety, and right here community defenses got here into play, Manrod mentioned. The corporate makes use of community detection and response instruments from Corelight and decryption instruments from Gigamon and Citrix Netscaler, amongst others.

“It is at all times unwise for any safety chief to declare with certainty or overconfidence, however we had a substantial amount of success with that multi-layer technique,” he mentioned.

There are privateness points with regards to inspecting visitors, Manrod mentioned, however that is the place organizations have to outline insurance policies about what they do and don’t need to see: “There are stuff you by no means need to decrypt,” he mentioned.

For instance, if enterprise customers are allowed to entry private banking or well being care websites on work units, or different issues of very private nature, these is likely to be off-limits.

However many different communications that aren’t sometimes inspected ought to be, Manrod mentioned. For instance, when attackers compromise enterprise software program, the again channels these functions use for their very own inside communications or updates could be problematic.

That is what occurred with SolarWinds: “There is a tendency to belief vendor-supplied updates, and an inclination to permit them an excessive amount of communication out, which attackers have compromised in a number of provide chain assaults.”

Inspecting outbound visitors

If extra enterprises had edge firewall insurance policies that prohibited outbound communications to anyplace besides express areas, the Photo voltaic Winds assault would have been blocked, Manrod mentioned.

And decrypting outbound communications ought to be even simpler than inbound ones, he added. “You management your endpoints and what certificates are deployed on them and what insurance policies are in place.”

In line with the Zscaler report, attackers use encrypted channels to exfiltrate knowledge, like stolen private and monetary data, and to connect with command-and-control servers.

“Many IT directors enable full outbound web entry from inside machines, which is a threat to the community,” defined Matthew Parsons, director for community and safety product administration at Sungard Availability Providers.

He recommends that knowledge middle cybersecurity managers lock down all outbound web visitors so servers cannot ship knowledge offsite, and use inside servers for pushing patches and updates.

“For the servers that do have to provoke outbound entry to the Web, configure them to solely have the ability to entry particular patching IPs or domains,” Parsons advised Information Middle Information. “And, as a greatest follow, make the most of a proxy for enhanced visibility and management over outbound visitors.”

Watching lateral actions

East-to-west, lateral visitors is an even bigger downside than both inbound or outbound communications, Grand Canyon’s Manrod mentioned.

“Attackers are good at utilizing cryptography and atypical communication strategies,” he mentioned. “Or utilizing anticipated communication strategies and residing off the land.”

With inside communications between two items of malware, each ends of the communication channel are below the attacker’s management, to allow them to use sturdy encryption to cover messages. In fact, simply the truth that suspicious processes are sending secret messages to at least one one other inside your community could possibly be an indication that one thing fishy is happening.

Most visitors inspection instruments are designed to watch incoming and outgoing visitors – not inside visitors on the community.

Continuously encrypting and decrypting visitors at each step can create community bottlenecks and trigger efficiency issues. On the similar time, ignoring community encryption creates a major visibility subject for safety groups.

Zero-trust architectures and community segmentation are presently the go-to solutions to the issue of lateral motion, however some distributors are beginning to supply centralized SSL decryption options that cut back processing and administration overhead.