What Is a Backdoor Attack?
Essentially, the term “backdoor” refers to any remote access to a device without authorization. This backing meaning is following the concept of a “backdoor” to a home that allows intruders access.
Backdoor attacks refer to somebody “breaking in” using that backdoor access. Hackers will not break into a house. Instead, they will break into a device. Instead of taking physical items, they will be stealing sensitive data.
Backdoor attacks can be motivated by several elements. The backdoor attackers could be part of governments, organizations, or just ordinary hackers. The identity of the attacker is usually linked to the reason for the backdoor attack and the intended goal.
Some of the reasons for using a backdoor attack may include:
- Surveillance
- Sabotage
- Data theft
- Launching of malware attacks
- Cryptojacking
How Does a Backdoor Attack Work?
Typically, devices don’t come equipped with backdoors for obvious reasons. However, a backdoor attack involves the installation of a backdoor into a device. This can be done in a variety of different ways, including:
- Installing a backdoor on the device’s firmware or hardware
- Using malware
- Exploiting the device’s software vulnerabilities
Backdoor attackers may try to steal data. Depending on the target, however, they may have more malicious aims once they have gained access to the network. It is important to understand that a system vulnerability can be used to create a backdoor. This enables a backdoor attack to occur.
Firstly, it’s crucial to understand the different types of backdoors and how a backdoor attack works. Secondly, it’s essential to figure out if you and your devices are vulnerable. After determining your level of vulnerability, you can finally establish the best way to prevent yourself from becoming the victim of a backdoor attack.
A backdoor attack is dependent on the type of attack initiated and how the hacker enters the system or application. There are two general ways in which you can enter a system - physically using malware or exploiting a vulnerability in the system.
A cyber-attack that attempts to exploit vulnerabilities in a system is commonly referred to as a zero-day exploit in cybersecurity terms. A dodgy backdoor website or suspicious online advertising is commonly used to stealthily scan your system and detect any vulnerabilities.
These vulnerabilities could include:
- Out-of-date software
- Weak passwords
- Open ports
- Weak firewalls
Once a vulnerability is found, the hackers can easily gain access to the system and do as they please.
Types of Backdoors
Different kinds of backdoors can be used to gain access to a device. Each backdoor follows specific kinds of attacks and being able to distinguish between them is the first step to detecting a backdoor attack.
These are a few different types of backdoors that may be used in a backdoor attack:
A Cryptographic Backdoor
A cryptographic backdoor attack uses a tool very similar to a master key that can access every room in a house. Just like a master key can unlock any door you choose, a cryptographic backdoor acts as a universal access provider to all encrypted data on a device.
Data is usually protected by AES 256-Bit encryption and various other algorithms. In this case, a cryptographic key is given to both the communicating parties involved - with the function of the key being to decrypt the security encryption and access the data within.
In a cryptographic backdoor attack, the security is breached which allows the hackers to access the cryptographic key and gain access to all the data that was meant to be secured by the network’s encryption.
Hardware Backdoors
With a hardware backdoor attack, a component of the device is altered in some way. This includes computer chips, hard drives, CPUs, and other elements. This method provides attackers with root-level access to the device and its systems.
Non-computer hardware can also be used in this way if its components have been altered and are linked to a system. These include cell phones, home security systems, thermostats, and other devices.
When this happens, attackers can gain access to a device, its systems, and the data that is found within. A hardware backdoor is usually used for surveillance capabilities or to gain remote access.
Rootkits
Rootkits are a more advanced backdoor attack method and require significant expertise to work effectively. This backdoor attack uses a concealed identity to access a system – by simply hiding your own identity or taking the form of another.
Rootkits work to trick operating systems into believing that they are trusted users and then take control from the inside. The disguise allows the hackers to control the system remotely and make it perform specific actions - including downloading systems, monitoring events, modifying files, and other orders.
While they are more complex to operate than other backdoor attacks, rootkits are also a lot more dangerous. If used properly, they can take the form of any used computer chip or software.
Additionally, since rootkits make use of stolen identities, they can be very difficult to detect. This means that they can spend a significant amount of time in the system without being detected - causing considerable damage and creating multiple potential data breaches.
Trojan backdoor
A Trojan backdoor is probably the most well-known backdoor attack method. Its name comes from the infamous wooden Trojan horse used by the Greeks as a disguise to attack the city of Troy.
Much like the legend of the ancient Greeks, a Trojan backdoor infiltrates systems using malware disguised as trusted files.
The files used to disguise the malware are usually reliable and don’t require extensive security analysis. This means that the malicious files are given immediate access to the system without their presence even being detected.
Once the files are in, users will generally receive a pop-up that reads something like, “Allow *insert program here* to make changes to your device?”
At this point, users are still unaware that the software they’re dealing with isn’t what they think it is and once permission is granted, a Trojan backdoor can be created - leading to a backdoor attack and bad news for the system in question.
A Trojan backdoor is commonly known as one of the most dangerous attacks as it can be very difficult to detect. Additionally, once inside, Trojan backdoors provide attackers with high-level admin access – allowing them to cause havoc without restriction.
Examples of Backdoor Attacks
Innovation within the world of technology has led to significant risks too and over the years, there have been many more occurrences of cybersecurity breaches – including a rise in infamous backdoor attacks.
Here are some examples of the backdoor attacks used before:
PoisonTap
More potent than many other forms of malware, PoisonTap provides attackers with access to your entire web search history - giving them the ability to view and access any website you’ve logged into.
Moreover, PoisonTap is capable of getting into systems that are secured even with multi-factor authentication. This backdoor attack example is a particularly dangerous type with the potential to cause serious damage.
However, PoisonTap can only gain access through a Raspberry Pi computer – a low-budget, single-board computer plugged into the main physical device’s USB port.
Developed by the infamous hacker-turned-hero Samy Kamkar, PoisonTap is yet to be used as a tool in any large-scale or widespread cyber-attack.
DoublePulsar Cryptojacking
DoublePulsar was initially developed by the US National Security Agency (NSA). However, in 2017, it was discovered that the program was being used to monitor users’ Windows PCs by installing a cryptojacker - targeting only PCs with sufficient processing power and CPUs.
Essentially, the DoublePulsar cryptojacker allows the attacker to steal the processing power of the PC and use it to mine Bitcoin. In doing so, this backdoor attack example connects to thousands of PCs around the world, creating a massive crypto-mining Botnet.
Dual_EC
Possibly one of the most well-known recent examples of a backdoor attack is the Dual_EC, which was also developed by the NSA. Using a highly advanced method to generate random numbers through complex mathematics, the Dual_EC created a formula called the elliptic curve which was then used to encrypt data.
At the time, this method of data encryption was believed to be incredibly secure and was widely promoted by the NSA - pushing multiple large companies around the world to start using Dual_EC to guard their data.
However, the Dual_EC included a cryptographic backdoor that could be accessed by higher-level users with the secret key that the NSA possessed.
In 2013, Edward Snowden went public with this information. He shared evidence with the world of how the NSA had motivated global corporations to adopt this method of encryption - giving them access to their private data and allowing the NSA to intercept any files and communication that was encrypted using Dual_EC.
This affected numerous corporate giants including Microsoft, Cisco, and Blackberry - whose millions of users' personal information and data were found to be accessible by the NSA.
Are you Vulnerable to Backdoor Attacks?
The most important question to ask yourself is, are you vulnerable to backdoor attacks? Unfortunately, the answer is yes. Most users have several vulnerabilities that make them susceptible to becoming the next victim of a backdoor attack.
These include weaknesses in:
- Devices
- Online accounts
- Appliances that are plugged into the Internet of Things (IoT)
- Networks
Since there are so many vulnerabilities that could be exploited by attackers, there are now several potential security measures that can be used to install backdoors onto devices. When it comes to targeting vulnerabilities in a system, there are certain things that backdoor attackers will focus on:
Gullible Users
The easiest way for hackers to gain access to your device is if you give them access. The internet is full of traps for gullible users – enticing links, torrent websites, and free downloads, to name a few. It saves the attacker’s time and the user probably won’t even realize they’ve allowed hackers access to their device until it’s too late.
Weak Passwords
The importance of having strong passwords cannot be stressed enough. Once hackers have gained access to one account, it’s not difficult for them to get into other accounts on the same device.
Usually, hackers use default passwords to play a numbers game where botnets scan the internet for IoT devices that are using default passwords – something like “Password” or “1234”. Once found, those devices are under the control of the botnet which can wreak havoc.
This is the easiest and most common way that ordinary people can become the victim of a backdoor attack. If there's one thing you can do to secure yourself, it's to make sure that your passwords are strong and never use the same password for multiple devices or applications.
Open Network Ports
Open network ports represent the risk of a potential backdoor attack, which is more of a concern for businesses and tech-savvy individuals rather than ordinary users. Most home users’ router ports are closed by default but those who allow their router ports to remain open are putting themselves at risk.
Open network ports are a vulnerability which makes it an ideal target location for hackers to install a backdoor. In an attempt to go unnoticed, attackers will often target ports that are being used to prevent users from being notified by any security software.
However, there are ways in which users and businesses can protect themselves by using specific software. Sangfor offers professional assistance in this regard so your business can make use of open ports without the risk of a cyber-attack.
Hidden or Legitimate Backdoors
While they’re often manipulated, backdoors do have some legitimate uses. It's not uncommon for software developers to include hidden backdoors in the software they sell to provide remote support at a later stage. The important part of this, however, is that these backdoors are secure.
Unfortunately, hackers have been known to gain access to even these harmless types of backdoor installations. Additionally - like the backdoor attack example of Dual_EC that was exposed by Edward Snowden - there have been cases of companies intentionally allowing backdoors to be accessible for their benefit.
Outdated Software
Software update notifications can be annoying, but they’re there for a reason. If you haven’t updated your software, your device and systems cannot be sufficiently protected, and you may become the target of a cyber-attack.
One of the best ways to protect yourself and your device is to simply ensure that your software is always updated.
Best Ways to Prevent a Backdoor Attack
Unfortunately - like most cyber-attacks - no one is completely immune to becoming the victim of a backdoor attack. However, there are many ways to respond to a backdoor attack. With the appropriate knowledge and expertise, you can ensure effective backdoor cybersecurity for your network.
After dealing with the immediate threat, the most important thing to do is to assess the damage. This will allow you to implement a damage control protocol - which will also help you to prevent similar attacks from being successful in the future.
Since backdoor attacks make use of both complex and simple methods, there are a series of tactics that can be used to prevent yourself from becoming a victim:
Using Anti-Virus Software
It may seem obvious, but having updated anti-virus software installed on your device can help detect a cyber-attack and prevent it from causing any damage. It can easily deal with backdoor malware such as Trojans, rootkits, spyware, and cryptojackers.
Advanced anti-virus software provides Wi-Fi monitoring, web protection, and microphone and speaker privacy monitoring.
Cybersecurity Awareness
Encourage your employees and yourself about the proper cyber hygiene practices that need to be in place. Always be wary when downloading files or attachments. Ensure that the website you’re using is official and protected.
Making Use of a Firewall
A firewall is one of the best ways to monitor any potential backdoor activity. It can detect any third party trying to access your device, or if your device is attempting to send data out to any unknown network location. A firewall is most effective because it can block any kind of suspicious activity automatically.
Sangfor’s Next Generation Firewall (Sangfor Network Secure) can be used in conjunction with Endpoint Security to identify malicious files at both the network level and endpoints. The advanced firewall is a security device designed to inspect network and application traffic for threats, secure the network environment from intrusion, and bring in security intelligence from outside the network.
Using a Password Manager
Not only do password managers make your life a lot easier, but they also provide you with a layer of extra security - especially when it comes to preventing a backdoor attack
By providing one master password, users allow the application itself to generate sophisticated and complex encryptions for all other applications. This makes it very difficult to hack into and prevents the possibility of a backdoor attack.
Trust Sangfor to Prevent Backdoor Attacks
If you’re concerned about a hacker gaining access to your device or system via a backdoor, Sangfor provides an array of solutions and platforms that will ensure maximum security.
The most important step to staying safe is to understand what a backdoor attack is and how it works. This will help you to understand how these attacks can be initiated and the steps you can take to prevent them.
Invest in high-quality cybersecurity with Sangfor Technologies and never be caught lacking by a backdoor attack again. For more information on Sangfor’s cybersecurity and cloud computing solutions, visit www.sangfor.com.
