What Is a Rootkit and How to Remove It?
A rootkit is malicious software code that gives bad actors "root" access to an endpoint device by breaching application and driver privilege levels to reach the kernel or core while concealing the harmful code. This article defines rootkit and describes how to remove and avoid infections.
What is a Rootkit?
A rootkit is usually a malicious piece of software that gives root-level (administrative) access to a computer while hiding the fact that it is there. It’s a nasty type of malware that can make your PC run very slowly and put your personal information at risk.
Once installed, a rootkit usually starts up at the same time as the computer’s operating system, or after the boot process has started. There are, however, rootkits that can start up before the operating system they are meant to protect. This makes them very hard to find.
Some possible results of a rootkit are:
- Concealed malware – Rootkits let attackers add more malware to computers that are already infected. They hide malicious programs from users and any anti-virus software that is installed on a computer.
- Information theft – Malicious software that has been installed with the help of a rootkit can be used to steal user passwords, credit card numbers, and other sensitive information without being noticed.
- File deletion – Rootkits can delete files, including operating system code and other files on a system.
- File execution – Once anti-malware software has been turned off on a system, rootkits let criminals run other files on target computers from afar.
- Eavesdropping – Hackers can use rootkits to listen in on users and steal their personal information by eavesdropping on their conversations
- Remote access – Rootkits can change the way a system is set up. For example, they can open backdoor TCP ports in firewall settings or change the way startup scripts work. This gives attackers remote access, so they can use the computer as part of a botnet, for example.
How Rootkits works
Since rootkits can’t spread on their own, they use secret ways to get onto computers. When users who don’t know what they’re doing let rootkit installer programs run on their computers, the rootkits install and hide themselves until hackers use them. Rootkits have bad tools in them, like tools that steal banking credentials, passwords, keystrokes, turn off antivirus software, and bots that do distributed denial-of-service attacks.
Rootkits are installed in the same ways as other malicious software, such as through phishing emails, malicious executable files, malicious PDF or Word documents, connecting to shared drives that have been hacked, or downloading rootkit-infected software from risky websites.
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Different kinds of Rootkits
Here are six different kinds of rootkits.
1. Rootkit hardware or software
This kind of rootkit gets its name from where it is put on your computer. This kind of malware could infect your computer’s hard drive or system BIOS, which is software that is installed on a small memory chip on your computer’s motherboard. Even your router can get it. Hackers can read data that is written to the disc with the help of these rootkits.
2. Bootloader rootkit
The bootloader on your computer is a very useful tool. When you turn on your computer, it loads the operating system. Then, a bootloader toolkit attacks this system and puts a hacked bootloader in place of your computer’s real one. This means that this rootkit is turned on before your computer’s operating system starts up.
3. Memory rootkit
This kind of rootkit hides in the RAM, or Random Access Memory, of your computer. In the background, these rootkits will do things that are bad. What’s good? These rootkits only work for a short time. They only exist in your computer’s RAM and will go away when you restart your system, though sometimes more work is needed.
4. Rootkit for applications
Application rootkits replace normal files on your computer with files that are used by the application. They could also change how regular programs work. Some of these rootkits could get into Word, Paint, or Notepad. Hackers will be able to get into your computer every time you run one of these programs. The problem is that the infected programs still work as usual, which makes it hard for users to find the rootkit.
5. Kernel mode rootkits
These rootkits try to get into the operating system of your computer. These are tools that cybercriminals can use to change how your operating system works. All they have to do is add their own code. This can make it easy for them to get into your computer and steal your personal information.
6. Virtualized rootkit
These rootkits are malicious software that run as a hypervisor and control one or more virtual machines (VMs). Rootkits work differently on a virtual machine (VM) with a hypervisor than they do on a real computer. In a VM environment, the VMs that are controlled by the master hypervisor machine seem to work normally, and the service or performance of the VMs that are linked to the hypervisor doesn’t seem to change. This lets the rootkit do its bad work with less risk of being found, since all VMs that are connected to the hypervisor look like they are working normally.
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Rootkits attacks examples
OS attacks. When a kernel mode rootkit gets into a system, it can attack the OS. The attack can change the way the OS works, slow down the system’s performance, or even access and delete files. Kernel mode rootkits usually get into a system when a user opens a malicious email by accident or runs a download from a source they don’t trust.
Social engineering and phishing – Rootkits can get on computers when people open spam emails and download harmful software by accident. Rootkits also use keyloggers to get login information from users. Once a rootkit is installed, hackers can get to private user information and take control of computer operating systems.
Attacks on the network and the internet of things (IoT) – IoT devices and edge computing pose major security risks because they don’t have the same security measures that other systems and centralized computers do. Hackers put in rootkits through edge points of entry to find and use these weaknesses. This can let a rootkit spread through a network and take over computers and workstations, turning them into zombie computers that can be controlled from outside the network.
Thefts and scans of credit cards. Rootkits have been used by thieves to get into credit card readers and swipers. The rootkits are set up to record credit card numbers and send them to servers that hackers control. To stop this, credit card companies have started making cards with chips that are harder to hack.
Applications rootkits – Rootkits can be installed on popular programs like spreadsheet and word processing software. When a user opens an app that has been infected with a rootkit, the hackers can get to their information.
| Read more: Keyloggers and how to prevent from keylogging
- 1990: Lane Davis and Steven Dake make the first known rootkit for the SunOS Unix OS at Sun Microsystems.
- 1999: Greg Hoglund writes an article about how he made the first rootkit for Windows, a Trojan called NTRootkit. It is an example of a virus that works in kernel mode and is called a rootkit.
- 2003: HackerDefender, a rootkit that works in user mode, comes out for Windows 2000 and Windows XP. RootkitRevealer and HackerDefender played a game of “cat and mouse” when HackerDefender came out.
- 2004: A rootkit is used to tap over 100 mobile phones on the Vodafone Greece network, including the phone used by the country’s prime minister. This attack, which would come to be known as “Greek Watergate,” was carried out by a hacker group called “Fancy Bears.”
- 2005: Sony BMG is hit with a huge scandal after giving out CDs that install rootkits as a way to stop piracy without getting permission from customers first.
- 2008: the TDL-4 bootkit, which was called TDL-1 at the time, was used to power the notorious Alureon Trojan, which is used to build and run botnets.
- 2009: The proof-of-concept was in 2009. Machiavelli rootkit attacks macOS, which was called Mac OS X at the time. This shows that Macs can also be affected by malware like rootkits.
- 2010: The Stuxnet worm, which the US and Israel are said to have made together, used a rootkit to hide itself while attacking Iran’s nuclear program.
- 2012: In the Middle East and North Africa, a 20 MB piece of modular malware called Flame wrecks infrastructure. This is a big piece of malware, since most are under 1 MB.
- 2018: LoJax is the first rootkit to infect a computer’s UEFI, which is the firmware that controls the motherboard. This means that even if the operating system is reinstalled, LoJax will still be there.
- 2019: Scranos, a rootkit that steals passwords and payment information stored in your browser, is behind this recent rootkit attack. And, most importantly, it turns your computer into a clickfarm so that you can earn money and YouTube subscribers without anyone knowing.
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How to detect and remove Rootkits
Because rootkits are so dangerous and hard to find, you should be careful when browsing the internet or downloading programs. You can’t protect yourself magically from all rootkits.
Luckily, you can increase your chances of avoiding these attacks by using the same common-sense steps you use to avoid other computer viruses. We have complied some of the steps here, please read and follow it carefully.
1. Look for signs of a rootkit attack
If your device has one of the following warning signs, it may have a rootkit:
- Unusual behavior on your network system – Hackers can change your computer’s operating system by using rootkits to change how it works. If your device is acting strangely, it could be because a hacker put a rootkit on it.
- Changes in settings – In theory, your device shouldn’t do anything unless you tell it to, and you should be the one telling it what to do most of the time. Someone with a rootkit and remote monitoring could change your settings and configurations. Something that looks different, like an extra program running when a device boots up, could be a reason to worry.
- Intermittent web page or network actions – If you have trouble getting online more often than usual, it might not just be a service problem. If a hacker uses a rootkit to send or get a lot of information from your computer, it could slow down your connection.
2. Find out where the rootkit is
If you think your computer has a rootkit, try one of these ways to find it:
- Attempt signature scan – Computers use numbers to scan signatures, which is called “signature scanning.” A piece of software’s signature is a string of numbers that describe it in computer language. You can check for pop-ups by running a scan against a list of known rootkit fingerprints.
- Memory dump analysis – When your Windows PC crashes, it makes a memory dump, which is also called a crash dump. A skilled expert can look at these files to figure out what caused the crash and if a rootkit was to blame.
- System memory search – Check the system memory of your device to see if something is wrong. Check all points of entry or access for signs of activities that were called during the inquiry, and keep track of any library operations that were imported from dynamic-link libraries (DLLs). Some of them can be linked together or turned away to do other things.
3. Make sure Rootkits don’t get into your system
The easiest way to avoid having to get rid of a rootkit infection is to stop the attack from happening in the first place. Among the things you can do, you can:
- Never open files that look suspicious. Even files from people you trust should be carefully looked over before you open them. Be careful with attachments from people you don’t know, because they could be online scams.
- Purchase software from reputable source. Like the website of the software maker, the App Store, or the Google Play Store. Check the terms and conditions carefully to make sure no one will try to install a rootkit on your system. You may also purchase software, tools and other digital products from this, apphut.io
- Update your system as soon as possible. These updates come out often to fix newly discovered holes that attackers can use to get into the device.
4. Remove the device and reinstall the operating system
If an antivirus program and a check at boot time don’t get rid of the rootkit, you might want to back up your data, wipe your device, and reinstall the system software from scratch. When a rootkit is running at the boot, firmware, or hypervisor level, this is often the only thing that can be done. Before you can back up your important files, you need to know how to format and copy a hard disc. You might have to clean up the central C: disc, but you should be able to keep most of your data. This is the very last thing you can do to get rid of a rootkit.
5. Try boot-time scanning
Modern malware uses sophisticated methods to avoid being found by antivirus software. Once the operating system is installed, rootkits on the device can trick automatic virus checks. When an antivirus program asks the operating system to open a certain malicious file, the rootkit can change the data flow and open a safe file instead. They can also change the identification code of a malware file, which is used to store and share malicious information. This makes it harder for a scan to find it.
This is why a scan at startup is so helpful. Rootkits are caught before they can do anything by scans that happen when your device starts up. A boot-time scan can find rootkits while they are still inactive and can’t hide on your computer.
6. Run Rootkit removal software
Don’t depend on Windows Defender or other built-in security software because most rootkits can get around simple defenses. For complete safety, use software with a lot of features. These will combine powerful cyber threat-detection systems with anti-malware software based on artificial intelligence into a single, lightweight program that can find and remove rootkits and protect against online attacks in the future.
Rootkit removal software runs a number of scans to make sure that rootkits and other types of malware don’t get on your computer. It will know how to get rid of and stop rootkit viruses from coming back. Before a thief steals your data or gets privileged access to the machine, let the software check for and get rid of the infection for good.
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Tips to prevent Rootkits attacks
Even though it’s hard to spot a rootkit attack, a company can protect itself in the following ways:
- Use powerful antivirus and antimalware software. Most of the time, rootkits can only be found with specific add-ons to antimalware software or with software designed to find rootkits.
- Update your software regularly. Rootkit users always check operating systems and other systems for security holes. OS and system software makers know this, so as soon as they find a security hole in one of their products, they send out a security update to fix it. As best practice, IT should update software as soon as a new version comes out.
- Network monitoring. Network monitoring and observability software can immediately notify IT if there is an unusually high level of activity at any point along the network, if network nodes start going offline all of a sudden, or if there is any other sign of network activity that could be seen as unusual.
- Behavior analysis. Rootkits are less of a threat when companies make strong security permission policies and keep checking to make sure they are being followed. For example, if a user who usually logs into a system during the day in San Jose, California, suddenly logs in at night in Europe, a threat alert could be sent to IT so that they can look into it.
When it comes to getting into a computer system, rootkits aren’t much different from other online threats. But once they get into the system, they change completely. Getting rid of them is very hard, so you don’t want to have to do it. Because of this, it’s always a good idea to be careful when surfing the web and reading emails.