Most businesses now utilize Excel and other software programs for their day-to-day operations, but many don’t realize using such applications comes with a risk. Many programs such as Microsoft Word and Excel operate using a macro language that allows them to function smoothly with great convenience.

It’s that same language that can also allow macro viruses to invade systems and create complete pandemonium in a business network. Here’s what to know about macro viruses and methods for preventing them from turning your network into a hot mess.

The Trouble with Macro Languages

When it comes to working with programs that utilize macro language is that their greatest benefits are also one of their biggest security flaws. The programs allow you to import documents from other people with ease which can be very convenient but is also a risk.

For example, in the financial world, people often use Excel to share documents on a regular, ongoing basis. When your Excel program reaches out for those documents, they can bring nasty macro viruses along with them. That means that your Excel documents and computer systems can also become infected.

What is a Macro Virus?

A macro virus is a computer virus written in the same macro language as the software program it is meant to attack. This includes programs such as Microsoft Word and Excel which are written in macro languages. Because these programs are embedded with macro languages, they are able to automatically open documents and pull shared files from other people.

When a macro virus infects a file such as an Excel document, it has the potential to damage the document and even other computer software. If a document is opened that has been infected, the macro virus will automatically begin a series of actions to begin wreaking its havoc.

How Macro Viruses Spread

While macro viruses can be spread through phishing email attachments containing the virus, they can also be spread through external references, also known as links, according to a blog by Norton. The virus will access the files in your address book in order to send infected emails to all of your contacts, further proliferating the virus.

Since the email will appear to come from a credible source, many people will open it. Once it is opened, it can then infect the next person’s computer and their documents. Macro viruses run on applications, not on operating systems. Common methods for spreading macro viruses include:

  • Downloading a file by modem and opening it
  • Downloading a file through an internet or intranet connection and opening it
  • Opening an attachment in an email
  • Sharing files on a network
  • Sharing files on a disk

As with other malware and viruses, macro viruses can be hard to detect. As a result, macro viruses are the stealthy digital version of herpes and a macro virus infection can ultimately leave your business dead in the water.

Excel Macro Viruses

One of the inherent dangers of Excel is that there are macro viruses that target this program that can be spread easily. In Excel, an external reference is a reference to a cell or range on a worksheet in another Excel workbook.

If you or your computer pulls an external reference from the Excel workbook of another, you could be pulling over a macro virus as well. Take for example a certified public accountant (CPA) who pulls over part of an Excel workbook from a client. Their computer may even do it automatically on a set schedule for bookkeeping purposes.

Should that Excel document happen to be infected when it is pulled over, it can infect the current workbook, all Excel documents, and even other computer software within the computer network.

Stopping Macro Viruses

Always be aware of where you are pulling information, or external references, from and why it’s necessary. Never pull documents, open attachments, or click on links from unknown or untrusted sources.

Second, your macro language programs will alert you if there are external references in a document and will ask for your permission to enable them. A security dialog box will appear if there are external references in a document. Click “enable” only if you are sure the document is from a trusted source.

Also be sure to install updates to your computer security system as soon as they are available to guard against newly identified threats. Ensure your computer’s operating system is updated on a regular basis and select reliable security software to block macro viruses and other threats.

Finally, employ digital signatures. This helps identify download sources to help ensure the files you’re downloading are less of a risk.

Signs of a Macro Virus Infection

There are several cues that may signal a macro virus infection. These indicators may be a clue that a macro virus infection has occurred:

  • Your computer begins running slower than normal.
  • A request for a password on a file that normally doesn’t require one.
  • Your computer saves documents as “template” files.
  • Your computer begins to display strange error messages.

If you think your computer has been infected, contact your IT department or third-party IT partner such as ORAM Corporate Advisors immediately. They can assist you with opening a document in “safe mode” to check if macros are present and can remove it if there is an infection before more damage is done.

For more information about macro viruses or cybersecurity for your business, contact ORAM Corporate Advisors now at (617) 933-5060 for a free initial consultation.