What is a Backdoor and How to Prevent Backdoor Virus Attacks?

A backdoor refers to any method that allows users to bypass standard authentication procedures or encryption on a device. Let’s see how you can prevent backdoor virus attacks.

A backdoor creates an alternative entry point into a device, a network, or software that grants remote access to resources such as databases and file servers.

Hackers scan the web for vulnerable applications which they use to install backdoor viruses. Once installed on your device, a backdoor virus can be hard to detect because files tend to be highly obfuscated.

The existence of a backdoor in your device gives perpetrators the ability to remotely carry out a variety of hacking purposes such as:

• Surveillance
• Device hijacking
• Malware installation
• Financial information theft and
• Identity theft

How Do Backdoor Virus Attacks Work?

A backdoor can be installed legitimately by software and hardware developers to help them easily access their applications in order to perform functions such as resolving software issues.

But in most cases, backdoors are installed by cybercriminals to help them gain illegitimate access to a device, a network, or software application.

For cybercriminals to successfully install a backdoor virus on your device, they must first find a weak point (system vulnerabilities) or a compromised application in your device.

Some common system vulnerabilities include:

• Unpatched software
• Open network ports
• Weak passwords
• Weak firewalls

Vulnerabilities can also be created by a piece of malware like trojans. Hackers use trojans existing on a device to create backdoors.

A trojan is a type of malicious program often disguised as legitimate software to steal data or install a backdoor. Using some form of social engineering, it tricks users into downloading and opening the trojan on their devices.

Once activated, a backdoor trojan gives hackers remote control over the infected device. They can carry out all sorts of malicious activities, including stealing, receiving, and deleting files, rebooting the device, and installing other malware.

Once cybercriminals have hacked and cracked their way into your computer through a backdoor infection, they’ll want to make sure they can easily re-enter it — whether that’s to steal your information, install crypto mining software, hijack your device, or sabotage your business.

And hackers know it can be difficult to keep re-hacking a device, especially if the vulnerability gets patched. That is why they install a code called a backdoor on the target device so that even if the vulnerability is fixed, the backdoor remains to let them into the device.

How Hackers Use Backdoors Virus Attacks Today

Hackers gain access to your device through various backdoor intrusion techniques like port binding, connect-back approach, connection availability abuse, and standard service protocol approach – it’s pretty complicated. Still, it involves deceiving your device, firewall, and your network.

Once the backdoor virus has been installed, hackers can perform malicious activities like:

• Ransomware malicious software that infects your device and prevents you from accessing your personal files unless you pay a fee, usually in the form of bitcoins.
• DDoS (Distributed-Denial-of-Service) attacks malicious attempts to disrupt and render a website or online service unavailable by flooding and crashing it with too much traffic. This traffic may include connection requests, fake packets, and incoming messages.
• Spyware software with malicious intent infiltrates your device. It collects almost any form of data, including personal information such as bank or credit account information, internet surfing habits, usernames, and passwords.
• Crypto-jacking, also called malicious crypto mining, is an online threat that hides in your computer or phone and uses its resources without your knowledge to mine online currencies like bitcoin for someone else.

Real-World Examples of Successful Backdoor Attacks

#1. MarcoStyle YouTube Channel Hacking

A YouTuber named MarcoStyle was hacked back in 2019 when he replied to an email from a company looking to advertise on his channel. The company appeared legit, but when Marco clicked on a link attached to the email, an installer buried itself in his computer. He noticed something was wrong with his PC almost immediately, and he cut off the power, did a fresh Windows install, and changed his login information.

Unfortunately, the hackers had already gotten to his Google account and extracted his YouTube channel from his Gmail, which had over 350,000 subscribers.

Marco notified YouTube but not before his channel was sold on a Russian website for hacked YouTube channels. They changed his profile picture and name to “Brad Garlinghouse” and took down all his videos. Five days later, the hackers started a live stream in which they reportedly stole about $15,000 from Marco’s viewers.

They even managed to get verified by YouTube, something Marco had tried countless times but was denied. It took eleven days after the hack for YouTube to get Marco’s channel back.

This is an example of how hackers use malicious links as a common way to install backdoor viruses on devices.

#2. The WannaCry ransomware attack

WannaCry ransomware attack in 2017 is probably the best example of how hackers can launch a backdoor virus attack on a company when patches are not applied.

The attack, which affected more than 230,000 computers across 150 countries, was propagated through EternalBlue, an exploit developed by the NSA for older windows. A hacker group known as Shadow Brokers stole EternalBlue, installed DoublePulsar backdoor, then encrypted the data, and demanded $600 worth of bitcoin as a ransom payment.

Microsoft had released the patch that protected users against this exploit for several months, but many affected companies, including the NHS hospital, failed to apply it. Within a few days, thousands of NHS hospital surgeries across the UK were disrupted, and ambulances were rerouted, leaving people in critical conditions unattended.

As a result of the attack, 19,000 appointments were canceled, costing the NHS a whopping £92 million. The Wannacry attack was estimated to have caused $4 billion in losses across the globe.

A few companies who paid the ransom got their data back, but research shows that most did not.

#3. SolarWinds Sunburst Backdoor Attack

On December 14, 2020, malicious backdoors known as Sunburst and Supernova were discovered in SolarWinds. SolarWinds is a major information technology company based in the United States that creates software to help businesses manage their networks, systems, and IT infrastructure.

Cybercriminals hacked into Texas-based SolarWinds systems and added malicious code into the company’s software Orion — a software system widely used by companies to manage IT resources.

Unknowingly, SolarWinds sent out Orion software updates to its customers that included malicious code. When customers downloaded the updates, the malicious code installed itself and created a backdoor to their devices which hackers used to spy on them.

SolarWinds reported that 18,000 of its 300,000 customers were impacted by the backdoored Orion software. The insured losses from the attack were estimated to be $90,000,000, making it one of the most significant cybersecurity attacks ever.

#4. Backdoors  Found on iPhones

In a 2020 study by Ohio State University, New York University, and Helmholtz Center of Information Security, thousands of Android apps contain a backdoor. Out of the 150,000 apps tested, 12,705 showcased secret behavior indicating the presence of a backdoor.

Types of backdoors found included access keys and master passwords that could allow remote unlocking the app and resetting the user’s password. Some apps were also found with the ability to execute secret commands remotely.

Backdoors in phones make it easy for cybercriminals and the government to spy on you. They can lead to a total loss of data and unrecoverable system damage.

Are you Vulnerable to Backdoor Virus Attacks?

Unfortunately, most people have plenty of flaws on their online accounts, networks, and even Internet of Things (IoT) appliances that make them vulnerable to backdoor virus attacks.

Below are a variety of techniques hackers exploit to install backdoors on user devices.

#1. Hidden/legitimate backdoors

Sometimes, software developers purposely install hidden backdoors to give them remote access to carry out legitimate activities such as customer support or addressing software bugs. Hackers scan for such backdoors to gain illegitimate access to the software.

#2. Open network ports

Hackers scan for open network ports to exploit because they can accept traffic from remote sites. Once they get into your device through an open port, they leave backdoors that allow them access to your device again and again without detection.

You need to identify ports you want running on your server and restrict them, then close or block ports that are not in use to prevent them from being exposed on the internet.

#3. Unrestricted file uploads

The majority of web servers allow you to upload pictures or pdf files. A backdoor vulnerability occurs when you fail to restrict files uploaded to only the intended file type.

This creates a backdoor for cybercriminals to upload an arbitrary code to the webserver so they can come back any time and execute any command they want. The best way to fix this vulnerability is to validate the type of file that a user can upload before accepting it.

#4. Command injections

Another type of vulnerability that could lead to a backdoor virus attack is command injection. In this type of attack, the hacker aims to execute a command on the target device by exploiting a vulnerable web application. It is tough to detect this type of backdoor infection because it is not easy to tell when a malicious user is trying to attack a device.

The most effective way to prevent command injection vulnerabilities is to use a strong user input validation that prevents improperly formed data from entering a system.

#5. Weak passwords

Weak passwords like your birthday or the name of your first pet are easy for hackers to crack. What’s worse is most people use one password for all of their online accounts, which means if hackers get a hold of the password to one account, it can be easier to gain control of all your other accounts.

Weak or default passwords on your IoT devices are also an easy target for cybercriminals. If they get control of, say, a router, they can find the WiFi’s password stored on the device, and the attack gets pretty serious from there —often leading to DDoS attacks.

Take the time now to update the default password of your router and WiFi PSK and change the admin password for all IoT devices in your network.

More Ways to Prevent Backdoor Attacks

A backdoors virus attack can go undetected for a long time because they are pretty difficult to detect — that’s how hackers design them. Even so, there are a few easy steps you can take to keep your device safe from backdoors virus attacks.

#1. Use an Antivirus

Sophisticated antivirus software can help detect and prevent a wide range of malware, including trojans, crypto hackers, spyware, and rootkits frequently used by cybercriminals in deploying backdoor attacks.

Good antivirus includes tools like WiFi monitoring, an advanced firewall, web protection, and microphone and webcam privacy monitoring to ensure you’re as safe as possible online.

This means that your antivirus software will detect and eliminate a backdoor infection before it can infect your machine.

#2. Download with Care

When downloading software, files, or apps, pay attention to the permission request to install (free) additional bundled applications. These are called PUA (Potentially Unwanted Application) — free software, files, and apps that appear to be legitimate but are not. And they are often packaged with a type of malware, including backdoor viruses.

Consider installing an online security software with real-time malware detection and always download from official websites and avoid clicking on third-party download (pirate) sites.

#3. Use Firewalls

Most antivirus software are equipped with a firewall that can help protect against attacks such as backdoor viruses.

Firewalls are designed to monitor all incoming and outgoing traffic on your network so they can filter out threats.

For instance, a firewall can tell when an authorized user is trying to access your network or device and will prevent them from doing so. Firewalls can also be set to block any application on your device that tries to send your sensitive data to an unknown network location.

#4. Use a Password Manager

A password manager can help you generate and store login credentials for all of your accounts, as well as assisting you in automatically logging into them.

Password managers use a master password to encrypt your password database, so you don’t need to type in your password, email, or username every time. All you have to do is save your passwords on the password manager and then create a master password.

When signing in to any of your accounts, you need to type in the master password, which automatically fills in the data. And most password managers have a feature that notifies you when your data has been breached and when the password you are using has been found in a stockpile of stolen user data.

#5. Stay on Top of Security Updates/Patches

Hackers abuse known flaws or weaknesses in a device or software. These weaknesses can exist because of a lack of updates. Statistics show that one in three breaches are caused by vulnerabilities that could have already been patched.

Another study shows that 34 percent (one in three IT professionals) in Europe reported their organizations had suffered a breach due to unpatched vulnerability.

Fortunately, software developers frequently publish new patches to fix the vulnerabilities in their software, and they include auto-update settings or give notifications about updates.

Turn on automatic updates because it’s essential to keep your operating system updated because backdoors depend on fooling your OS.

#6. Use Multi-Factor Authentications (MFA)

Multi-factor authentication is designed to improve security by preventing unauthorized access.

It requires you to confirm your identity in more than one way when accessing an application, website, or software.

MFA uses three essential elements to prove your identity:

• Something that only you know, like a password or pin
• Something that only you have, like a token or your smartphone
• Something that only belongs to you, like your thumbprint, voice, or facial features

For example, when logging into an account with a password, you might get a notification on your phone asking you to tap your screen to approve the request.

You can also be required to use your password and fingerprint or the iris of your eye when logging in to your accounts.

Final words 👩‍🏫

Once installed on your device, backdoor viruses can be hard to detect because files tend to be highly obfuscated. And they create ways for perpetrators to access your sensitive information and install other forms of malware.

The good news is there are ways you can keep yourself safe from backdoor virus attacks.

For instance, you can use a good anti-malware solution or monitor your network activity for any weird data spikes resulting from an intruder attempting to hack your device using a backdoor. And you can also use firewalls to block all unauthorized connections to your network.