There are some very valid reasons why you should block access to file sharing websites. These websites are mainly used to share pirated software, music, films, and TV shows. It would be improbable that the owner of the copyright would take action against an employer for failing to stop the illegal sharing of copyrighted material, but this is an unnecessary legal danger.

However, the chief risk from using these websites comes in the form of malware. Research completed by IDC in 2013 indicated that out of 533 tests of websites and peer-2-peer file sharing networks, the downloading of pirated software lead to spyware and tracking cookies being downloaded to users’ computers 78% of the time. More concerning is the fact that Trojans were downloaded with pirated software 36% of the time.

A survey carried out on IT managers and CIOs at the time showed that malware was downloaded 15% of the time with the software.  IDC found that overall there was a 33.3% chance of infecting a machine with malware by using pirated software.

Even browsing on torrent sites can be harmful. This week Malwarebytes said that visitors to The Pirate Bay were shown malicious adverts. An advertiser used a pop-under to silently redirect users to a malicious site that had the Magnitude exploit kit which was used to install Cerber ransomware onto users’ devices.

A study completed by UC San Diego involved testing pirated software downloads using VirusTotal. VirusTotal reviews files against the databases of 47 different anti-virus services. The research team found that 50% of pirated files were infected with malware.

Dealing with malware from pirated software was found to take around 1.5 billion hours per year. For companies the cost can be considerable. IDC estimated the cost to enterprises to be around $114 billion in 2013 alone. And that was just for the clean-up. The cost of data breaches caused by illegal software installations was calculated at around $350 billion.

Groups can monitor devices and check for unauthorized software downloads on individual devices; however, by the time a software installation has been identified, malware is likely to already have been downloaded. A recent report by Verizon indicates that on average, hackers are able to extract data within 28 minutes of obtaining access to a system.

One of the simplest ways to manage risk is to block file sharing websites including P2P and torrent sites. A web filter can be easily set up to block file sharing websites and stop them from being accessed. Many web filters can also be set up to block specific file types from being installed, including keygens and other executables.

By preventing access to file sharing websites organizations can ensure that copyright-violating activities are stopped and malware risk is effectively handled. Additionally, web filters can be used to block web-borne threats including phishing websites, compromised webpages, spam and botnets, adware, malware, ransomware, and anonymizers.

Choosing not to block file sharing websites could turn out to be expensive for a company. It is far better to block possibly dangerous websites and online activities than to have to cover the cost of removing malware infections and managing with data breaches.