NAS Ransomware Guide: How to Protect Your NAS From Attacks

A decorative image showing a NAS device locked up with chains. The title reads NAS Ransomware.

You probably invested in a network attached storage (NAS) device to centralize your storage, manage data more efficiently, and implement on-site backups. So, keeping that data safe is important to you. Unfortunately, as NAS devices have risen in popularity, cybercriminals have taken notice.  

Recent high-profile ransomware campaigns have targeted vast numbers of NAS devices worldwide. These malicious attacks can lock away users’ NAS data, holding it hostage until a ransom is paid—or the user risks losing all their data. 

If you are a NAS user, learning how to secure your NAS device against ransomware attacks is critical if you want to protect your data. In this guide, you’ll learn why NAS devices are attractive targets for ransomware and how to safeguard your NAS device from ransomware attacks. Let’s get started.

What Is Ransomware?

To begin, let’s quickly understand what ransomware actually is. Ransomware is a type of malicious software or malware that infiltrates systems and encrypts files. Upon successful infection, ransomware denies users access to their files or systems, effectively holding data hostage. 

Its name derives from its primary purpose—to demand a “ransom” from the victim in exchange for restoring access to their data. Ransomware actors often threaten to delete, sell, or leak data if the ransom is not paid. 

Ransomware threat messages often imitate law enforcement agencies, claiming that the user violated laws and must pay a fine. Other times, it’s a blunt threat—pay or lose your data forever. This manipulative strategy preys on fears and urgency, often pressuring the unprepared victims into paying the ransom. 

The consequences of a ransomware attack can be severe. The most immediate impact is data loss, which can be catastrophic if the encrypted files contain sensitive or critical information. There’s also the financial loss from the ransom payment itself which can range from a few hundred dollars to several million dollars. 

Moreover, an attack can cause significant operational downtime, with systems unavailable while the malware is removed and data is restored. For businesses, especially the unprepared, the downtime can be disastrous, leading to substantial revenue loss. 

A picture of Earth from space with light-up areas around cities.
Cybersecurity Ventures expects that by 2031, businesses will fall victim to a ransomware attack every other second. Source.

However, the damage doesn’t stop there. The reputational damage caused by a ransomware attack can make customers, partners, and stakeholders lose trust in a business that falls victim to such an attack, especially if it results in a data breach. 

As you can see, ransomware is not just malicious code that disrupts your business, it can cause significant harm on multiple fronts. Therefore, it’s important to understand the basics of ransomware as the first step in building a robust defense strategy for your NAS device.

Types of Ransomware

While the modus operandi of ransomware—to deny access to users’ data and demand ransom—remains relatively constant, there are multiple ransomware variants, each with unique characteristics. 

Some of the most common types of ransomware include:

Locker Ransomware

Locker ransomware takes an all-or-nothing approach. It locks users out of their entire system, preventing them from accessing any files, applications, or even the operating system itself. 

The only thing the users can access is a ransomware note, demanding payment in exchange for restoring access to their system. 

Crypto Ransomware

As its name suggests, crypto ransomware encrypts the users’ files and makes them inaccessible. This type of ransomware does not lock the entire system, but rather targets specific file types such as documents, spreadsheets, and multimedia files. The victims can still use their system but cannot access or open the encrypted files without the encryption key. 

Ransomware as a Service (RaaS)

RaaS represents a new business model in the dark world of cybercrime. It is essentially a cloud-based platform where ransomware developers sell or rent their ransomware codes to other cybercriminals, who then distribute and manage the ransomware attacks. The ransomware developers receive a cut of the ransom payments.  


Leakware steals sensitive or confidential information and threatens to publicize them if ransom is not paid. This type of ransomware is particularly damaging as even if the ransom is paid and the data is not leaked, the mere fact that the data was accessed can have significant legal and reputational implications. 

A decorative image showing several stacked cubes with some of them breaking apart.
Only 4% of victims who paid ransoms actually got all of their data back. Source.


Scareware uses social engineering to trick victims into believing that their system is infected with viruses or other malware. They scare people into visiting spoofed or infected websites or downloading malicious software (malware). While not as directly damaging as other forms of ransomware, scareware can be used as the gateway to a more intricate cyberattack and may not be an attack in and of itself. 

Can Ransomware Attack NAS?

Yes, ransomware can and frequently does target NAS devices. These storage solutions, while highly effective and efficient, have certain characteristics that make them attractive to cybercriminals. 

Let’s explore some of these reasons in more detail below.

Centralized Storage

NAS devices act as centralized storage locations with all data stored in one place. This makes them an attractive target for ransomware attacks. By infiltrating a single NAS device, bad actors can gain access to a significant amount of company data, maximizing the impact of their attack and the potential ransom.

Security Vulnerabilities

Unlike traditional PCs or servers, NAS devices often lack robust security measures. Most NAS systems may not have an antivirus installed, leaving them exposed to various forms of malware including ransomware. Additionally, outdated firmware can further weaken the device’s defenses, offering potential loopholes for attackers to exploit. 

Always Online

NAS devices are designed to be continuously online, allowing for convenient and seamless data access. However, this also means they are constantly exposed to the internet, making them a target for online threats around the clock. 

Default Configuration Settings

NAS devices, like many other hardware devices, often come with default configurations that prioritize ease of access over security. For example, they may have simple, easy-to-guess default passwords or open access permissions for all users. Not changing these default settings can leave the devices vulnerable to attacks. 

Risk Factors: The Human Element

NAS devices are an easy-to-use, accessible way to expand on-site storage and manage data, making them attractive for people without an IT background to use. However, novice users, and even many of your smartest power users, may not know to follow key best practices to prevent ransomware. As humans, all of us are vulnerable to error. In addition to NAS devices having some unique characteristics that make them prime targets for cybercriminals, you can’t discount the human element in ransomware protection. Understanding the following risks can help you shore up your defenses: 

Lack of User Awareness

There is often a lack of awareness among NAS users about the potential security risks associated with these devices. Most users may not realize the importance of regularly updating their NAS systems or implementing security measures. This can result in NAS devices being unprotected, making them easy prey for ransomware attacks. 

Insufficient Backup Practices

While NAS devices provide local data storage, it has to be noted that they are not a full 3-2-1 backup solution. Data on NAS devices needs to be backed up off-site to protect against hardware failures, theft, natural disasters, and ransomware attacks. If users don’t have an off-site backup, they risk losing all their data or paying a huge ransom to get access to their NAS data. 

Lack of Regular Audits

Conducting regular security checks and audits can help identify and rectify any potential vulnerabilities. But, most NAS users take regular security audits as an afterthought and let security gaps go unnoticed and unaddressed.

Uncontrolled User Access

In some organizations, NAS devices may be accessed by numerous employees, some of whom may not be trained in security best practices. This can increase the chances of ransomware attacks via tactics like phishing emails.

An image of a computer with a lock in front of it. Several phishing hooks are attacking from all angles.
Up to 70% of phishing emails are opened by the recipient. Source.

Neglected Software Updates

NAS device manufacturers often release software updates that include patches for security vulnerabilities. If users neglect to regularly update the software on their NAS devices, they can leave the devices exposed to ransomware attacks that exploit those vulnerabilities.

How Do I Protect My NAS From Ransomware?

Now that you understand the NAS devices vulnerabilities and threats that expose them to ransomware attacks, let’s take a look at some of the practical measures that you can take to protect your NAS from these attacks.

  1. Update regularly: One of the most straightforward yet effective measures you can take is to keep your NAS devices’ applications up-to-date. This includes applying patches, firmware, and operating system updates as soon as they’re available and released by your NAS device manufacturer or backup application provider. These updates often contain security enhancements and fixes for vulnerabilities that could otherwise be exploited by ransomware.
  2. Use strong credentials: Make sure all user accounts, especially admin accounts, are protected by strong, unique passwords. Strong credentials are a simple but effective way to avoid falling victim to brute force attacks that use a trial and error method to crack passwords.
  3. Disable default admin accounts: Like we discussed above, most NAS devices come with default admin accounts with well-known usernames and passwords, making them easy targets for attackers. It’s a good idea to disable all these default accounts or change their credentials. 
  4. Limit access to NAS: Most businesses provide wide open access to all their users to access NAS data. However, chances are that not every user needs access to every file on your NAS. Limiting access based on user roles and responsibilities can minimize the potential impact in case of a ransomware attack. 
  5. Create different user access levels: Along the same lines of limiting access, consider creating different levels of user access. This can prevent a ransomware infection from spreading if a user with a lower level of access falls victim to an attack. 
  6. Block suspicious IP addresses: Consider utilizing network security tools to monitor and block IP addresses that have made multiple failed login attempts and/or seem suspicious. This can help prevent brute force attacks. 
  7. Implement a firewall and intrusion detection system: Firewalls can prevent unauthorized access to your NAS, while intrusion detection systems can alert you to any potential security breaches. Both can be crucial ways of defense against ransomware. 
  8. Adopt the 3-2-1 backup rule with Object Lock: Like we discussed above, NAS devices offer a centralized storage solution that is local, fast, and easy to share. However, NAS is not a backup solution as it doesn’t protect your data from theft, natural disasters, or hardware failures. Therefore, it’s essential to implement a 3-2-1 backup strategy, where three copies of your data is stored on two different types of storage with one copy stored off-site. This can ensure that you have a secure and uninfected backup even if your NAS is hit by ransomware. The Object Lock feature, available with cloud storage providers such as Backblaze, prevents data from being deleted, ensuring your backup remains intact even in the event of a ransomware attack.

The Role of Cybersecurity Training

While technical measures are a crucial part of NAS ransomware protection, they are only as effective as the people who use them. Human error is often cited as one of the leading causes of successful cyber-attacks, including ransomware. 

This is where cybersecurity training comes in, playing an important role in helping individuals identify and avoid threats. 

A photo of network cables.
Studies have shown that in 93% of cases, an external attacker can breach an organizations network perimeter and gain access to local network resources. Source.

So, what kind of training can you do to help your staff avoid threats?

  • Identification training: Provide staff members with the knowledge and tools they need to recognize potential threats. This includes identifying suspicious emails, websites, or software, and understanding the dangers of clicking on unverified links or downloading unknown attachments, and also knowing how to handle and report a suspected threat when one arises. 
  • Understanding human attack vendors: Cybercriminals often target individuals within an organization, exploiting common human weaknesses such as lack of awareness or curiosity. By understanding how these attacks work, employees can be better equipped to avoid falling victim to them. 
  • Preventing attacks: Ultimately, the goal of cyber security training is to prevent attacks. By training staff on how to recognize and respond to potential threats, businesses can drastically reduce their risk of a successful ransomware attack. This not only helps the company’s data but also its reputation and financial well-being. 

Also, it is important to remember that cybersecurity training should not be a one-time event. Cyber threats are constantly evolving, so regular training is necessary to ensure that staff members are aware of the latest threats and the best practices for dealing with them.

Protecting Your NAS Data From Threats

Ransomware is an ever evolving threat in our digital world and NAS devices are no exception. With the rising popularity of NAS devices among businesses, cybercriminals have been targeting NAS devices with high profile ransomware campaigns. 

Having a comprehensive understanding of the basics of ransomware to recognize why NAS devices are attractive targets is the first step toward protecting your NAS devices from these attacks. By keeping systems and applications updated, enforcing robust credentials, limiting access, employing proactive network security measures, and backing up data, you can create a strong defense line against ransomware attacks.

Additionally, investing in regular cybersecurity training for all users can significantly decrease the risk of an attack being successful due to human error. Remember, cybersecurity is not a one-time effort but a continuous process of learning, adapting, and implementing best practices. Stay informed about the latest NAS ransomware types and tactics, maintain regular audits of your NAS devices, and continuously reevaluate and improve your security measures. 

Every step you take towards better security not only protects your NAS data, but sends a strong message to cybercriminals and contributes towards a safer digital ecosystem for all. 


About Vinodh Subramanian

Vinodh Subramanian is a Product Marketing Manager at Backblaze, specializing in cloud storage for Network Attached Storage (NAS) devices. As an engineer turned product marketer, Vinodh brings technical knowledge and market insights to help readers understand the benefits and challenges of protecting NAS data. Through his writing, Vinodh aims to empower businesses to make informed decisions about storing, protecting, and using data with ease. Vinodh lives with his family in Arizona and enjoys hiking and road trips in his free time.