What is Mirai?
Mirai (The Japanese word for ‘Future’) is a nasty IoT (Internet of Things) malware that scans for insecure routers, cameras, DVRs, and other Internet of Things devices which are still using their default passwords and then add them into a botnet network, which is then used to launch DDoS (Distributed Denial of Service) attacks on websites and Internet infrastructure.
Originally this malware could only infect Linux based systems. The new versions can now infect Windows computers and spread itself to IoT devices on a network.
How Mirai works?
Mirai is built for 2 core purposes:
- Locate IoT devices to grow the botnet.
- Launch DDoS attacks based on instructions received from a remote C&C (Command and Control Center).
To fulfill its recruitment function, Mirai performs wide ranging scans on IP addresses. The purpose of these scans is to locate under-secured IoT devices that could be remotely accessed via easily guessable login credentials—usually factory default usernames and passwords (e.g., admin/admin). When the login succeeds the identity of the new BOT and its credentials are sent back to the CnC.
The CnC then copies the Virus into new device and commands the BOT to attack the new victim by sending massive amount of data. This results in what is called a Distributed Denial of Service (DDoS) attack. A DDoS attack uses all of the devices in its “army” to then attack a target and flood it with traffic. When a website is flooded with too much traffic it can then be taken offline and users cannot access it.
How does Mirai affect the System?
Infected devices are hard to recognize as they continue to function normally except for occasional sluggishness and an increased us of bandwidth.
However, the Mirai is a severe IoT malware that can be used for launching DDoS attacks massively and cause real havoc on the Internet infrastructure worldwide.
How to Protect Your System against this Malware?
- On an average IoT devices are scanned every two minutes. This means that a vulnerable device, such as one with a default password, could be infected within minutes of going online. So preventive measures should be taken to protect your system against this self-propagating harmful virus.
- Users are firmly advised to secure IOT devices with strong and unique passwords.
- Installing a reputable Internet security program could be one more way to guard your system against this venomous malware.
Threat Summary
Name: Mirai
Browsers Affected: Mozilla Firefox, Google Chrome, Microsoft Edge, Internet Explorer, Opera and Safari.
Targeted Operating System: Linux operating systems, IoT devices, Windows and Mac OS
Category: Trojan
Symptoms: Causes massive DDoS attacks, outage of popular websites, disables the Internet for thousands of people, occasional sluggishness of the infected device.
How to Remove Mirai from your computer system?
Step A: Remove the malicious program from Control Panel
Note: Before we begin, try to remember how the extension got downloaded on your computer system. Generally, these programs come bundled with free applications that we download off the internet. It is a good practice to locate and uninstall such programs while removing the Browser Hijacker/ Extensions.
Windows XP
- Click on the “Start” button on the bottom left corner of your screen. A Start menu will be displayed as shown below. From this menu select the option that reads “Control Panel”.

- In the window that will be displayed, click the option “Switch to classic view”.

- This will display all the options/icons available to you. From the displayed icons, click on the icon that reads “Add or Remove Programs”.

- Select the “Uninstall a program” option from the “Programs” category. A list will populate on the screen displaying all the programs.

- Select the programs related to Mirai and click on the Uninstall button.

Windows 7/Vista
- Right click on the “Start” button located at the lower left corner of the screen. From the Start menu, click on “Control Panel”.

- The “Control Panel” Window will be displayed on the screen. Click on “Uninstall a Program” option from the “Programs” category.

- The “Programs and Features” window will be displayed on the screen. A list will populate on the screen displaying all the programs.
- Scroll though the list of programs and select the programs related to Mirai and then click on the “Uninstall” button.

Windows 8/10
- Right click on the “Windows logo” on the lower left side of the computer screen. From the drop down menu, select and click on “Control Panel”.

- The “Control Panel” window will be displayed. From this window select “Uninstall a program” option form the “Programs” category.

- A list will populate on the screen displaying all the programs.

- Select the programs related to Mirai and click on the “Uninstall” button.

- In the confirmation box, click on the box that reads “OK” to save changes.
Step B: Show hidden files and folders.
Windows 7
- Left click on the Organize button on the Windows Explorer. A drop down menu will appear.

- On this menu left click on the option that reads “Folder and search options” as shown above. A folder options dialogue box will appear.
- On the View tab under the Advanced settings, Check the option that reads “Show hidden files, folders, and drives” and uncheck the option that reads “Hide protected operating system files“.

- Click on the “OK” button to save your changes. This will make all the hidden files and folders visible to you.
Windows 8 and 10
- On the file explorer toolbar, click on the View

- In the Show/hide section, Click on the “Hidden items” checkbox.
- Click on the options button.

- Under folder options, click on the “View” tab.

- Uncheck the “Hide protected operating system files” option.
- Click the “OK” button to save your changes.
Step C: Remove the Malware from the System Configurations settings
- Type “Msconfig” in search box / Run Box, select it and press Enter.
- Click on “Services” Tab and click on “Hide all Microsoft services”.

- Select Mirai from the list of remaining services and disable it by removing the tick mark from the checkbox and click on Apply button.
Windows 7
- Click on the next tab – “Startup”.
- Find any blank or suspicious entry or the entry with Mirai mentioned and remove the check mark.
- Click on Apply button and then click on OK.

Windows 10
- Click on the next tab – “Startup”.
- Take the mouse cursor to ‘Open task Manager‘ link and click on it. This opens the Task Manager window.

- Find any blank or suspicious entry or the entry with Mirai mentioned and click on it.

- Then click on Disable button.
Step D: Restore the Browser settings changed by Mirai
Google Chrome
- Open Google chrome and click on the three vertical dots (
) located on the top right corner of the Chrome Window.
- From the Drop down menu that appears, click on the “Settings”. A new browser tab will open up, displaying all the settings.

- Now, we will make changes to the appearance section. Under the “Appearances” section, we will enable the “Show Home Button” option. You can select New Tab page or can add Google or any of your preferred browsers under the “Show Home Button” option.

- After this, we will go to the “Search Engine “section.
- Here, make Google or any of your preferred browsers as your default browser in the drop-down menu under the option “Search engine used in the address bar”.

- After this click on Manage Search Engines. Now you can remove Other Search Engines that were added by the browser hijacker. Simply click the three vertical dots (
) and select the option “Remove from list”. 
- You can make Google or any other preferred browser as your Default Search Engine by clicking the three vertical dots (
) and clicking on the “Make default” option.

- At the end, we will go to the section “On Startup”. You can select the “Open the New Tab page” or can “Continue where you left off”. If you want to open a specific page or set of pages, select the option “Open a specific page or set of pages” and remove any pages added by the browser hijacker by clicking on the three vertical dots (
) and selecting “Remove”.
- Then, add Google or any of your desired URL in “Add a new page” option under the “Open a specific page or set of pages”.

- This is a very important step and we would like you to pay very close attention here. This step has to be repeated with all the shortcuts to the browser that you can locate; like your desktop, start menu and the shortcut pinned to your taskbar. Right click on the shortcut and a context menu will appear. On this menu select the last option that reads Properties.

- A Google Chrome Properties Dialogue box will appear as below. Replace whatever is there in the text box next to the label Target with the following: Make sure that inverted commas are included.“C:\Program Files (x86)\Google\Chrome\Application\chrome.exe”

- Click OK at the end to save the changes.
Mozilla Firefox
- Open Mozilla Firefox and click on the three horizontal lines (
) i.e. Open Menu located on the top right corner of the Firefox Window.
- From the drop down menu that is displayed, we have to right click on the (
) Options to open the window.
- Now, we will click Search, under the given options that are displayed in the left corner of the screen.
- You can choose Google or any of your preferred browsers as your default search engine to use in the address bar and search bar.

- Then, you have to go to the (
) General and under “startup” section to make sure that Firefox is your default browser.
- At the end, we have to add Google or your preferred URL in the box given under Home Page.

- After this, you have to right click on the browser shortcuts that you can locate like your desktop, start menu and taskbar to which the application is pinned. A context menu will appear. On this menu select the last option that reads Properties.

- A Firefox Properties Dialogue box will appear as below. Replace whatever is there in the text box next to the label Target with the following: Make sure that inverted commas are included.“C:\Program Files (x86)\Mozilla Firefox\firefox.exe”

- Click OK at the end to save the changes.
Internet Explorer
- Open Internet Explorer and click on the gear icon (
)which is at the top right corner of the Internet Explorer Window.
- From the Drop down menu that appears, click on the “Manage add-ons” A new browser tab will open up, displaying all the add-on types.

- Now, we will click on the “Search Providers” option from the list of options displayed on the left hand side of the screen. Then we will click “Find more search providers” option given at the lower left corner of the Manage add-ons

- This will open an Internet Explorer Gallery; from here you can add Google search or any of your preferred add-ons as your default browser.

- Next, you are required to go to the “Manage add-ons” window and click on the “Search Providers” option under the Add-on Types.
- Here, you can enable Google Search or any of your preferred browsers as your default browser in the list of search providers.

- At the end, we will click on the gear icon (
)which is at the top right corner of the screen and select “Internet Options” from the drop-down menu.
- A new window will open displaying the Internet options. In the “Internet Options” window, add Google or any of your desired URL under the Create Home Page option and click OK.

- After this, you have to right click on the browser shortcuts that you can locate like your desktop, start menu and taskbar to which the application is pinned. A context menu will appear. On this menu select the last option that reads Properties.

- An Internet Explorer Properties Dialogue box will appear as below. Replace whatever is there in the text box next to the label Target with the following: Make sure that inverted commas are included.“C:\Program Files\Internet Explorer\iexplore.exe”

- Click OK at the end to save the changes.
Step E: Delete the suspicious file from the Registry Key:
- Type “Regedit” in search box / Run Box, select it and press Enter.

- An authorization dialog box will appear, then you just have to click “Yes”. (The dialog box appearance may vary depending on OS used. For Windows 10 the the dialog box looks like the first screenshot and for windows 7 it appears like the second screenshot)


- In the registry editor, take the backup of the current registry settings before making any changes in case you want to revert to old settings later. For this, Click on File option in the menu and select Export. Save the entry at a known location.

- From the Menu, Click Edit and Select Find.

- Enter Mirai and click on OK in the search box.

- Select and delete suspicious Enteries.
Step F: Removing the infection from the Target link:
The Malware may have hijacked your web browser’s desktop shortcuts. In this case we will need to manually clean them by removing any links within the startup argument.
- Locate your web browser shortcuts (Desktop, Taskbar or Start Menu), then right-click on it and select Properties. To view the Properties menu for the browser shortcut pinned to your Taskbar, right-click on the browser shortcut from the Taskbar. Right-click again on the browser icon and Select Properties.

- In the Shortcut tab, in the Target field, remove the url argument for Mirai which starts with “http”. There should be only the path to the browser’s main file and end with .exe such as iexplore.exe, chrome.exe or firefox.exe These are the default shortcut path that should be there in your Target box, if there is anything else you should remove it.

Tips to prevent your computer system from getting infected –
- Keeping the Operating System Updated- In order to remain protected and avoid such infections, it is recommended to keep your Operating System updated by enabling the automatic update on your system. The systems with outdated or older versions of Operating System become an easy target for the attackers.
- Resist clicking on spam emails – One of the major techniques used for malware distribution is forwarding spam emails to the user. The system gets infected as soon as the user clicks on the attachment. These mails appear to be genuine, so be aware and resist falling for these tricks.
- Keep an eye on third party installations- It is quite important that you take due care while installing any third party applications for they are major source of such infections. Such malware programs come bundled with the free applications thereby requiring the user to remain cautious.
- Regular periodical backup- In order to keep your data and files safe, it is recommended to take regular back up of all your data and files either on an external drive or cloud.
- Use Anti-Virus Protection- We strongly recommend the use of antivirus protection/internet security in your PC like 360 Total Security and BULL GUARD so that it remains safe.
- Enable the Ad Blocker/Popup Blocker in your browser- Enabling the popup blocker/ ad blocker in your chosen browser will help you to stay protected from annoying adware.
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