How Are Most Computer Viruses Spread?

Hackers constantly look for new ways to spread viruses, but their favorite distribution method is one of the oldest: unsolicited email. A recent report from Kaspersky Lab revealed that malware spam continues to grow as Web browser security improves and makes it harder to infect computers via websites.


Spam Trends

During the past year, the total quantity of unsolicited messages fell. However, the percentage containing virus attachments more than tripled. This greatly increases the likelihood that you or your employees will receive malicious communications in the near future.

Many harmful messages draw attention by focusing on terrorism and other events in the news. Some malware spammers have become more skillful in recent years. They personalize the information or try hard to make email appear as if it comes from legitimate organizations.

Kaspersky Labs reports that more and more email viruses install ransomware. When recipients open an attachment, this malware encrypts data on their PCs. It often proves difficult or impossible to recover the files without paying a “ransom” to hackers.

For example, one common email virus looks as if Microsoft sent it. The text claims that users can upgrade to Windows 10 by downloading an attachment. This file actually infects the recipient’s computer with ransomware and blocks access to every file on its hard drive, according to Fox.


Companies can protect their computers and data by educating office workers about safe Internet practices. Employees should learn to visit websites directly instead of using email links. They ought to carefully check messages for fake “from” addresses, unprofessional language and other suspicious attributes.

Businesses mustn’t rely on one-time trainings to warn staff members about Internet dangers. People eventually forget some of the advice, and viruses spread in different ways each year. Memos, newsletters and bulletin board notices can help keep employees informed.

A spam analysis expert at a major Internet security company recently said that “efforts to dupe victims are becoming more sophisticated year on year.” Consequently, it makes sense for office workers to contact the IT staff or a manager when they have any concerns about possible viruses.


Business owners and employees can sometimes avoid malware by using anti-virus utilities to scan files before opening them. However, such tools don’t succeed in detecting every virus. If in doubt, contact a sender by phone to confirm that he or she actually sent an attachment.

  • Never click on “unsubscribe” links in spam
  • Hackers may disguise malicious programs as photos
  • Don’t let Microsoft Word documents run macros

When sending messages to a group of staff members or contractors, always put their email addresses in the “bcc” field. Everyone can see all of the addresses under “cc” or “to”; if any recipient has a computer virus, it may gain access to the entire list.


Many commercial email services and programs let businesses activate and customize spam filters. You can stop malware from reaching inboxes by automatically returning messages sent from known spammers’ accounts. Consider blocking certain countries, IP addresses or domain names as well.

At the same time, be careful not to intercept normal correspondence. ReturnPath warns that filters block about one out of five legitimate messages people send to businesses. If you banish all email from an entire hosting or Internet service provider, this could discourage potential customers.

To sum it up, email-based viruses pose a growing threat that employers must take seriously. Filters, anti-virus programs and training can decrease the risk. Many business owners look to QualityIP when they want to stay up to date on the latest IT strategies and news. Please call (330) 931-4141 or contact [email protected] to learn more.