A macro virus affects macro languages programs e.g., MS Word, MS Excel, and all programs of MS document having macro languages. As soon as the application unlocks the virus activates itself. It can affect any computer such as Linux, macOS as it can affect the application so the operating system doesn’t matter. It can delete the file, modify the file and also send confidential information through email.
Macro viruses can keep themselves without the arbitration of the user and multiply through the help of the macro languages. Which document has the chance to be affected by the virus mostly? Word documents have the chance to be affected by the macro virus most often.
In this particular, you are going to learn about macro viruses; How Viruses will spread? How many types of macro viruses?
History of macro viruses
The macro viruses were discovered in July 1995. It was the virus that spread in the computer through Microsoft office in a CD-ROM known as “Microsoft compatibility test” and it was dispatched in August 1995. Until 2000 It was the demand virus of the century and then Microsoft incapacitates the macros by default. That’s the reason why attackers impose the authorization of macros to activate the virus.
How is it spread?
The macro virus spreads along with the document in embedded form or sticks in malicious code in a word document, files, etc., and insists the malicious code implement in a document. The virus also spreads through emails when the document is attached to it or through the phishing links in a website, URLs. As they are in embedded form so the detection is really difficult until the virus activates and performs its operations.
The macro virus affects other documents in a computer along with word documents.it causes disturbance in a computer by deleting, modification, etc. It can also replicate itself and affect other computers by sending malicious code through email to every associated person and affect their documents.
Frequent Sources of the spreading of the virus are:
- Through Email.
- Sharing files through the Internet
- Sharing on Networks
- Open file shared through Modems
- Sharing through Disks
Types of macro viruses
A macro virus is present in various forms but there are two frequent types and some called them the example of the macro virus.
- Concept virus
- Melissa virus
- Concept virus
The first type of macro virus is the concept that was discovered in July 1995 as we earlier studied. It is the dominant type and spreads through emails in a word document in the .doc extension. It can display a message when the document is affected. Version 95 or 6.0 of the MS word is affected by the concept virus. It was accidentally present in a CD-ROM.
- Melissa virus
The Melissa virus was released on 26 March 1999 and it is called a ‘mass mailing’ virus; it was not considered a worm. The virus entered into a system through emails written as a message from a user of the contact list. It can affect thousands of computers in no time and is considered the most dangerous virus in history. Microsoft 2000,97, and excel are the version affected by the Melissa virus
Principle of working
The working principle of the macro virus is: in a word document which is written in macro language the program enters into the system from where all the files open. The virus makes a copy of the macros which allows access to the main template. The auto file is stored in a new document and tries to obstruct the team and infect other files.
The infection activates due to the following reasons:
- The virus has access to the system macro.
- Activate when you open or close the system.
- By pressing the peculiar combinations of keys.
- Due to auto macro.
The virus activates all the programs in a macro language.
Algorithm of MS Word
The virus is present in the dot file and when the virus shifts, they are activated at the moment. The virus interrupts the normal working of the commands by countermanding the standard macros.
When the command is being called due to the infected file the command is infected. The file is converted to the template format and further change in the file is not possible and the virus overwrites the macros to its macros on the file.
Symptoms of the macro virus infection
The symptoms though we came to know about the infection in our system due to virus are following:
- The system works slow.
- Some files require a password even if it is not necessary.
- The system shows a strange pop-up.
- Documents are stored in the form of templates.
How to purify computers from macro virus
The file infected with the macro virus needs to be removed immediately to get rid of the virus. Rebooting your computer in safe mode is the initial step to remove the virus. All the temporary files should be deleted to free the disk space and speed up the scanning process. The virus scan is important for removal. If an already present antivirus is working and still the virus is not detected then use another method for scanning cause. If the existing anti-virus is enough for the detection then the malware is detected a long time ago in a system.
If the antivirus failed to detect the virus then use the manual method to remove the virus from the system to protect the documents. The reliable security software prevents the macro and protects the downloading of the malware in our system.
Steps to prevent the activation of the macro if exists in Excel and Word:
- Open the document by pressing the shift key.
- Select the ‘view’ option
- Click on ‘macros ‘and then’ organizer’
- Delete the infected file in a menu
Prevention against the virus
The macro virus usually presents in documents that have been shared through the internet by emails, links, phishing emails. The basic purpose of the antivirus is to prevent the virus along with the detection.
Certain methodologies used for the prevention of the macro virus are:
- Use reliable antivirus software that prevents the virus and also stops the user from downloading the files from the harmful links.
- Use the updated version of the software so that the new feature increases the protection of our system.
- A spam filter is necessary so that the suspicious links or emails decrease in number and the chance of the attack of the virus is less.
- Prevention to open the Files from the unknown sender.
- Do not open the file that is doubtful even from your known persons.
- Incapacitate the macros.
- To prevent the malicious file from the internet, use a digital signature.
- A proper security scan is needed for prevention.
Detection of the virus
The steps to detect the virus are as following:
- Save the document through ‘save As ‘is not possible.
- Any changes in the file do not transpire/occur.
- An error message displays while working on the document.
- The file does not save in another format.
- The ‘security level’ option is unreachable.
Along with the assistance of them, you can detect a virus, and then removal of the virus transpires.
A macro virus is a deadly virus from the moment it was introduced but there is also a method to prevent the virus from entering or to remove the virus if it is entered into our system. Our technology has been improving, so detection is not impossible. Our system is safe and sound due to these technologies. But viruses are not completely removed, they are present and the hacker is still using them for malicious reasons.