Prevent & block ransomware attacks on firewall

Ransomware is a malware attack that locks a victim’s data and demands a ransom, usually in Bitcoin, for its release. It often spreads through disguised executable files or malicious emails but can also exploit software vulnerabilities.

A notable instance is the WannaCry attack, which spread without user interaction. Given the increasing sophistication of these attacks, understanding and combating ransomware is crucial for tightened cybersecurity.

What is a ransomware attack?

Understanding the variants of malware and ransomware infections in cybersecurity is critical to effective prevention and response. These threats can range from viruses to sophisticated Ransomware-as-a-Service models. Let’s delve into the main types:

Viruses – Malicious software that can spread to other files and operating systems.
Worms – Self-replicating malware spreading independently through networks, causing significant damage.
Trojans – Disguised as legitimate software or files, Trojans can steal data or exploit permissions to gain unauthorized system access.
Adware – This malware displays unwanted ads or pop-ups on a system, often for the attacker’s revenue generation.
Fake pop-ups – Messages claiming your system has a virus and demanding payment for its removal, such as FakeAV and System Progressive Protection.
Rootkits – Designed to hide their presence, rootkits enable remote access for malware, making it difficult for antivirus software to detect and remove the threats.
Botnets – Attackers use these networks of compromised computers, known as botnets, to carry out remote DDoS and other cyber attacks.
Spyware – This malware secretly monitors user activity and collects sensitive data.
Fileless malware – Operating entirely in a system’s memory, this malware type is hard to detect and remove.
Phishing emails – Disguised emails that trick recipients into clicking a malicious link or opening email attachments that appear authentic.
Malvertising – Hackers inject malicious code into legitimate online advertising networks, redirecting users to malicious websites.
Drive-by attacks – Users visit unsafe, fake web pages, including sites infected unknowingly or fake sites posing as legitimate ones.
Self-propagation – Physically infects a system through a network or USB drive.
Encryption ransomware – Encrypts your files and demands payment in return for the decryption key. Examples include CryptoLocker and WannaCry.
Locker ransomware – A cyber threat restricting access to your system, demanding payment for restoring access. Winlocker and Police-themed ransomware are examples.
Mobile ransomware – Targeting mobile devices, this ransomware locks the device or encrypts the files, demanding payment for their release. Android Defender and Simplelocker are examples.
RaaS (Ransomware-as-a-Service) – Distributed as a service, this ransomware model allows anyone to buy or rent ransomware kits or apps for infecting others.

Recognizing these threats is the first step toward ransomware prevention.

What are the main types of malware and ransomware threats?

Yes, firewalls offer a layer of protection against ransomware. They act as a barrier between computers and networks, scanning incoming and outgoing traffic based on defined security parameters to block malicious packets.

Firewalls can help thwart ransomware attacks by blocking suspect IP addresses, prohibiting remote access without authorization, and controlling the flow of certain data types that could carry ransomware.

Are firewalls able to provide ransomware protection?

Several firewall rules can help block ransomware:

Block known malicious IP addresses – You can configure firewalls to block traffic from IP addresses known to often distribute ransomware.
Block all inbound traffic on port 445 – Used for file and printer sharing, port 445 is a common target for ransomware attacks.
Restrict outbound traffic – Limiting outbound traffic to necessary ports can prevent a ransomware attack from communicating with its command and control server, thus halting the attack.
Implement Geo-IP filtering – Some organizations may find it beneficial to block or limit traffic from specific countries or regions, particularly if they are known sources of ransomware.
Disable Remote Desktop Protocol (RDP) – Many ransomware attacks exploit RDP to gain remote access to systems. Disabling RDP at the firewall can help prevent these advanced threats.
Implement Intrusion Detection and Prevention Systems (IDS/IPS) – These systems can detect unusual traffic patterns or system activities that suggest a ransomware attack, allowing the firewall to respond and block the attack.
Application control – Firewalls with application control features can prevent the execution of unrecognized or unauthorized applications, which can stop the delivery or execution of ransomware.

Which firewall rules can block ransomware?

Clean up and tighten firewall rules

Over time, firewall rules can get messy. This mess might let attackers in, just like weak VPNs or vulnerable email security can. Regularly cleaning up firewall and endpoint protection rules can help stop a ransomware attack. When you change a rule, make sure you know why. Misconfigured changes could disrupt apps or expose VPN tunnels.

Analyze the risks and vulnerabilities in your network

Every network security solution has some risks. These risks come from different providers. It is essential to find these risks and rank them based on how much they can harm your business. Since threats can pop up anytime, endpoint security with anti-malware features is essential.

Focus on risks that could hurt critical business apps. Tying vulnerabilities to related firewall rules can make this easier, just like real-time updates in endpoint security can help stay ahead of new threats.

Mitigate lateral movement and control east-west traffic with network segmentation

Using network segmentation allows you to minimize the impact on your network in case of an attack. This is particularly effective against swift threats such as zero-day attacks, which target a software vulnerability that is unknown to the software vendor or to antivirus vendors. By securing crucial company data in protected segments with strong encryption keys and employing sandboxing, you are well-equipped to manage east-west traffic. East-west traffic refers to the communication or data transfer that happens inside the network, from server to server, or between internal applications. By managing this traffic, you can prevent attackers from moving laterally across your network.

Adding multi-factor authentication can make this strategy even more robust. It adds another layer of security to keep attackers under control. For enhanced protection against cyber threats, consider implementing micro-segmentation. This advanced method can provide granular security controls and can further deter lateral movement across your network.

Identify where your hybrid network is exposed to public networks

In complex network setups with multi-cloud and hybrid systems, it is very important to see everything that is happening. You need to know how your business apps connect, including any vectors that unwanted or harmful traffic, such as bots, could use.

To understand where your hybrid network is exposed to public networks, you need a complete map of your network and the ability to simulate traffic. This information can help you find and fix points where your network is exposed.

Respond to incidents coming from SIEM/SOAR solutions with rapid isolation

SIEM/SOAR systems collect and examine logs from your IT setup, security tools, and business apps. This helps the SOC team find and flag strange activities for further investigation. But with so much data, many alerts are false positives. Still, this does not mean you are lost in a sea of noise.

By linking security incidents to network traffic patterns, you can tell if a compromised server is exposed to the internet. This can help you quickly separate an infected server if a Trojan gets past your defenses, which is a crucial strategy in stopping ransomware attacks.

What are the best practices for ransomware prevention?

Step 1: Identify the attack – Act quickly if you think you are under a ransomware attack. Signs of an attack can include files you cannot open, weird computer activity, or a ransom message on your screen. If you see these, confirm it is ransomware and take steps to limit the damage.
Step 2: Isolate affected systems – When you know you are under attack, isolate the affected computers from the rest of your network. This can stop the ransomware from spreading. You might need to disconnect from the internet, turn off Wi-Fi, or even shut down the system.
Step 3: Secure backup data – Backups can help you recover from ransomware. If you have not already saved backups in a different place or offline, do it immediately to protect data from damage.
Step 4: Report the incident – Tell your IT department or security team about the attack. If you do not have an IT team, you might need help from a cybersecurity company. Also, tell the law enforcement agencies and any organizations you are a part of that might need to know.
Step 5: Preserve evidence – Keep any evidence related to the ransomware attack. This might include ransom messages, emails, or system logs. This evidence can help the police and cybersecurity experts understand what happened and might help get your data back.
Step 6: Remove the ransomware – IT or cybersecurity experts should be the ones to get rid of the ransomware. They have special tools and methods to remove ransomware. Experts will ensure that it does not cause more harm to your files or computers.
Step 7: Restore your systems – After the ransomware is gone, you can start fixing your systems. If you had backups that were not affected by the attack, you might be able to restore your systems to their previous state. If not, you might need a professional service to recover your data.
Step 8: Post-incident review – Review what happened and how you responded. Find any weak spots in your security that the attack exploited and make a plan to improve your safety. This step can help stop future attacks and strengthen your business’s cybersecurity.

What steps must you take when a ransomware attack is detected?

Manage security policies

AlgoSec’s tools help you deal with network security policies. They enable you to fight against ransomware attacks. AlgoSec makes sure your firewall does not have too many rules or unnecessary ones. Removing old or superfluous rules and eliminating duplicates will improve your anti-ransomware policies. Don’t forget to check out AlgoSec’s anti-ransomware resources.

Visualize your network

AlgoSec lets you see your entire network. It shows you all your business applications and how and where they connect. You can use this network map to find places that might be exposed to public networks and fix any weak spots.

Optimize security policies

AlgoSec gives you tools to improve your security policies. They help you clean up your firewall rules and remove old, duplicate, and too-permissive rules. AlgoSec’s intelligent change management automation and useful reports help you keep your policies clean. By ensuring new rules are designed and implemented optimally, potential ransomware attacks can be blocked.

Assess & mitigate risks

AlgoSec helps you find and deal with risks in your firewall policies. It checks your security policies against a list of best practices and known threats. By checking the risk of each new change before it is made, AlgoSec makes sure you do not accidentally add unknown risks to your network. This helps you protect your network from ransomware attacks.

Tie security incidents to business processes

AlgoSec’s platform smoothly integrates with all the leading SIEM and SOAR solutions. This lets you connect security problems directly to your business processes. If there’s a breach, AlgoSec quickly stops the attack by cutting off any servers at risk. This helps you limit the damage from a ransomware attack.

Enforce network segmentation

AlgoSec helps enforce network segmentation in your hybrid network. It automatically finds applications and their connections. This creates a real-time map for designing your network divisions. AlgoSec allows you to define which traffic is allowed, making sure your security rules fit your division strategy. It also automates security changes. The platform supports software-defined micro-segmentation control over network traffic, compatible with Cisco ACI and VMWare NSX.