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When it comes to malware, knowing what types of malicious software lurk out there can help you enable efficient cybersecurity measures and stay protected.

Backdoor malware is just one of many kinds of threats that you have to take into consideration when building your organization’s cybersecurity posture. The tricky part with this type of malware is that sometimes can take advantage of already embedded backdoors found in your devices’ software or even in the hardware.

In this article, you will discover what backdoor malware is, how it works and how to stay protected.

What Is Backdoor Malware?

Backdoor malware refers to a type of cybersecurity threat that can bypass security measures to access a network/ system/ device. Using backdoors, or entry points, cybercriminals can gain unauthorized access to data, critical systems, and other assets.

These types of incidents often remain undetected for a long period of time because no cybersecurity system is disrupted or tackled using brute force. Once in, a cybercriminal can install additional malware, steal important information, and has access to all of your company’s data.

Backdoors can be initially built into software by developers for positive use, so they can quickly access it to fix any problem, or can be created for malicious purposes by threat actors using malware. A computer system backdoor, in whatever shape it takes, is a security risk that may be easily exploited if discovered.

Types of Backdoors and How They Work

Even if their consequences can be equally disastrous, backdoors can have different origins: can be the result of malware or can be intentionally manufactured into software/ hardware.

Backdoor created by malware

This is malicious software that opens a backdoor in your systems for future cybercriminal endeavors. Usually, this type of malware reaches the user in the form of a trojan, being downloaded from the Internet or sent in an email attachment. As the name already tells us, a trojan is a malicious software that pretends to be an innocent file only to discover malware inside it.

Trojans can even replicate themselves, without any additional command, like a worm. They also give cybercriminals the opportunity to deploy a rootkit on the infected device. Using a rootkit, threat actors can hide their traces while accessing the infected systems again and again.

Built-in or proprietary backdoors

These type of backdoors are installed by the creators of the hardware or software themselves. Their initial purpose is to give easy access during the creation process. But, if they reach the general public by mistake or by criminal hand, they can be quickly weaponized by cybercriminals that will take advantage of this easy way of access.

Built-in backdoors can also be created at some point in the supply chain. This could happen while parts of hardware are shipped from one place to another or just before the finished product reaches the customer. When it comes to software, built-in backdoors can be created at the same time as any other part of the code used in a product.

How Backdoor Malware Can Harm You?

As I already said, once a cybercriminal is in, there is no way of telling what kind of harm will be done to your network. What we know is that by using backdoor malware, a threat actor can gain complete access to your systems and data, unbothered by security measures.

Here are just a few ways that a backdoor attack can evolve into:

Remote Access for Hackers

Backdoor malware can mean remote access to your systems and devices granted to a hacker for an unlimited period of time. Data can be exfiltrated without a visible hack in your company’s systems.

Highjack Your Computers’ Resources

Your computers’ resources can be hijacked by cybercriminals for malicious motives and this will slow down your systems without any apparent reason. The extra power can be redirected into a Distributed Denial of Service (DDoS) attack, or for cryptomining, for example, enlisting your device in a network of hacked computers, or a botnet.

An Open Door for Any Other Kind of Malware

Hackers can pick and choose what other type of malware to infect your network with. From ransomware, to spyware, tons of malicious software can be deployed on your company’s devices. So, you can discover that important information has been leaked, or that all your data has been encrypted, losing valuable content and money.

Get Lock Out of Your Own Systems

The total takeover of your systems is another scenario of a backdoor malware infection. Hackers can completely lock you out of your company’s systems by changing all the login credentials, as he has admin access to your endpoints and network. ‍


A backdoor is the perfect tool for cyberespionage acts: you don’t need proximity to your victim to steal corporate secrets, you can be on the other site of the world, and this reduces risks for the cybercriminals.

Sabotage Acts

If you don’t want to steal anything, but to create trouble and chaos, a backdoor malware can serve you well. State-backed hackers can carry out cyber warfare actions like sabotaging essential infrastructure for a nation: power grids, water filtration plants, missile systems.

How to Stay Protected from Backdoor Malware

Because taking preventive measures is better than dealing with backdoor malware, here are a few steps that you can take to stay safe:

Use Security Software

Anti-malware software or a firewall can stop malware from spreading and can detect unauthorized access to your systems or multiple failed login attempts. Make sure that you keep all your security software updated for the best protection.

Monitor Your Network Activity

One of the best ways to spot backdoor malware is to closely monitor your network in order to spot any suspicious activity, like weird data spikes. Once the alarm is raised, the network administrator can take immediate action to mitigate the breach. To add an extra layer of protection, make sure to enable two-factor authentication (2FA) for all your network resources.

Be Careful with Your Applications

One bad app, that contains a backdoor, can expose your whole network. That is why is best to download all your applications from a legitimate source like Google Play or App Store. And even then, you have to be careful to choose software with good reviews and to monitor the permissions for those apps.

Be Careful in Your Online Wonders

Unauthorized or unverified sites can deploy backdoor malware without you knowing it. So be extra cautious when surfing online, because even only visiting a malicious site can get you infected.

How to Remove Backdoor Malware

If you realize that a backdoor is maliciously used and harming you, there are a few steps you can take to remove the malware:

  • Start by backing up all your data on one or multiple locations, unconnected to the network or with each other.
  • Update your security software or install one that will serve the needs of your company.
  • It’s time for a malware scan on your site, network, endpoints, and systems. Disconnect your devices from the Internet before the scan. Any malware found during the scan will be removed by your anti-malware software.
  • Do a second scan to be sure that you are malware-free.

Don’t hesitate to file a legal complain with the authorities about this breach. If somebody accesses your computer without authorization, that is a crime, even if it’s happening because a mistake you made.

Alerting your colleagues and customers about this incident it is also important. By informing them, you give them the chance to be aware of any infection that might have affected them and can protect themselves.

Backdoor Malware Vs. Vulnerability

Vulnerabilities are flaws in the software that can be used by cybercriminals to enter into a system, get some control over it, exfiltrate data and deploy malware. While all these bad deeds can be done using backdoor malware, there are differences between backdoor malware and a vulnerability.

A vulnerability is an accident, or a software bug, it is created by mistake, but a backdoor is putted there with a purpose by cybercriminals or by manufacturers, and later used for malicious reasons.

How Can Heimdal® Help?

Heimdal Endpoint Detection and Response is a complex cybersecurity technology designed to protect endpoints and continuously monitor them for anomalies, as well as to respond to mitigate cybersecurity threats.

When threats arise, Heimdal’s EDR provides greater visibility into corporate endpoints and allows for faster response times, stopping an attack at its beginning.

Some of our most crucial modules are included in our EDR service (Threat PreventionPatch and Asset ManagementNext-Gen AntivirusRansomware Encryption ProtectionPrivileged Access ManagementApplication Control), ensuring the following features: automated detection and remediation, machine learning, threat intelligence, application control, patch and vulnerability management, privileged access management, intelligent alerting and reporting.

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Wrapping Up…

When backdoor malware acquires access to your endpoints or computer systems, it becomes risky, as it can be used by hackers to gain command of your devices and network. To fight against, identify, and remove such threats, use powerful anti-malware software, alongside with preventive measures.

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Author Profile

Andreea Chebac

Digital Content Creator

Andreea is a digital content creator within Heimdal® with a great belief in the educational power of content. A literature-born cybersecurity enthusiast (through all those SF novels…), she loves to bring her ONG, cultural, and media background to this job.

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