Container Security

Containers are small pieces of executable code commonly used in cloud software. Learn about container users and how to secure your containers.

When discussing computers, containers refer to a small piece of modular code. Containers are portable, which means the code can easily be deployed on any system. The container itself does not have any critical system information. Instead, it acts as a digital blueprint, containing the necessary code to run software. This means you can take a container and run it on any device because the code will reference your system code without requiring a specific system to operate. Most containers are only a few hundred megabytes in size.

Containers are used in a variety of programs, but are most commonly associated with microservices. Microservices are most commonly used in cloud programs, giving you access to a large volume of stored information without requiring you to download these services directly. Two of the most notable examples of microservices are Amazon and Netflix. With more applications relying on containers, security is a top concern.

Complexities of Container Security

Software protection is always important, but container security is more complex than other programs. A common misconception is containers are more secure than other applications. Unfortunately, this is not true. Container security is almost identical to any other application or system, so it is neither more or less difficult to protect. The complexity relates to performance. 

Containers work because they are small and fast. Adding security measures to containers risks making the application larger while also slowing down the code, defeating the point of using containers in the first place. Security settings are also not features easily added after creating a container. Modifications can be made to existing settings, but most developers prefer to build their security directly into the code when it is created. If there is a major security update, it is sometimes easier to create a whole new container instead of making modifications to an existing application.

Another issue is containers are built to be easily accessible. Adding too much security may isolate a container and prevent it from interfacing with your system. While these settings can typically be configured to allow access, it becomes an unnecessary complication for users. Fortunately, there are many companies and developers building container security.

Why Container Security is Important

At a glance, it may not seem like container security is important. Containers themselves are small pieces of code without any critical system information. However, containers are designed to interface with the rest of your system. Malicious individuals can put viruses and other harmful files in containers, which spread throughout your system. For example, if a keylogger infects your system, everything you type is recorded and sent to whoever generated the logger. Keyloggers use filters to search for sensitive information, such as credit card numbers, account passwords or Social Security numbers.

Common Container Threats

There are several common security threats to containers. Because containers are commonly used in cloud-based software, they are frequently targets of botnets. Bots are similar to containers. Both contain small amounts of code which perform specific tasks. Hackers use malicious bots, which act like a virus and spread through the system. Container bots spread quickly, creating a network known as a botnet, which can perform malicious tasks, such as denial of service attacks to overload website traffic until the site shuts down.

Another common container threat is authentication vulnerabilities. Containers are built with compatibility in mind, which means their code is designed to seamlessly interact with critical system files. Coders will use this to sneak dangerous programs or viruses in the container, bypassing your normal protection. Essentially, the container acts as a backdoor. This is especially devastating on a network, where the malicious code can spread throughout all the connected computers.

Best Security Practices

While there are many security options for your containers, there are also several steps you can take to keep your containers secure. While these are good practices, it is important to use them alongside traditional container security, not in place of. It may seem like a basic tip, but make sure you only download containers from a trusted source. Make sure you are also downloading the latest version, as older versions are more likely to have security vulnerabilities. 

If your business creates custom containers, try to keep the size small. Not only does a smaller size make the container easier to transfer, but it is also an easy way to spot any viruses. Like containers, viruses are often tiny files, which makes it easier to hide them in larger programs. With a container, it is easier to spot even tiny modifications.

Make sure to monitor your containers in real time. If your container is part of a cloud network, you must be able to spot security issues immediately to keep them from spreading on a wide scale. Prioritize software that sends immediate alerts and allows for real time monitoring.


Datadog is a popular container security service because it performs investigations in real time. Protection and detection services not only apply to the container, but also to any applications the container interfaces with, making it adept at detecting bot installation and similar threats. Datadog also interfaces well with communication and collaboration platforms commonly used by IT security. This allows your administrators to discuss and respond to a threat while keeping all the other administrators in the loop. A free 14-day trial is available, and there are also options for limited free accounts. A basic account starts at $15 each month per host.


Nearly every reviewer list of container security includes Anchore in the top three options. Anchore is largely aimed at cloud-based businesses that rely on containers to run. Anchore not only works with their own developers, but they also partner with members of the community to roll out security updates and address the newest vulnerabilities. Anchore largely specializes in running scans and updating to guard against new threats, but it does not have the same level of real time protection as other container security options. Anchore provides free demos, but you must request a custom quote for your subscription plan.

Aqua Security

Aqua is another group that focuses largely on cloud-based businesses. Aqua is available for both Linux and Windows containers and uses a combination of real time and scan-based security solutions. The company closely monitors your container as they are in use, spotting any potential backdoor threats while also providing feedback on the overall effectiveness of your container. Aqua also offers a host of other security options, which come at a discounted price. If you only want container security, the costs are based on node size, ranging from $.05 to $.33 cents per node.