The risk of external devices

Most of us own and use external devices for data transfers. Be it USB flash drives, external drives, cameras or mobile phones, they all make it easy and comfortable to transfer important data. On the other hand, they also bring a couple of security problems that we shouldn’t overlook.

The biggest risk point of external devices is first and foremost their content – it represents a threat to the system. There are loads of infected devices in the world, which, when plugged in, will activate ransomware or other harmful code. These codes can infiltrate the computer without any user action whatsoever – they covertly deploy as soon as the disk is attached to the USB connector. In other words, all that a user has to do to infect his/her computer and open the door to his/her data is to plug in an unknown device.

Playing into attackers' hands

This is why many organizations all around the world preventatively test their employees: they place unmarked external drives with fake harmful code around the company. Then they monitor which employees actually bring these media into the company and attach them to their work stations. To wise up careless employees to the security rules, a link to company policy usually opens on their screens.

Recently, a similar test was run at universities in the American states of Illinois and Michigan. Three hundred USB drives were distributed around the campuses and 45% - 98% of these devices were eventually carried away and plugged into computers at home or on university networks. These outcomes show us the context of the risk: if every second person is willing to thoughtlessly attach a completely unknown device, then an attacker doesn’t have to work too hard to compromise his victim’s computer. When organizing a targeted attack, he can just place a couple of USB devices in the area, and tick the task off his list.

Another risk is connected with employees not securing their personal and company memory media. When lost or stolen, unsecured devices open up their content to anyone who finds them and so provide the opportunity to misuse the data. Let’s just remember the case from a couple years ago when a flash disk with confidential Slovak army information was found near a bus stop.

This problem is bigger than it may seem. According to last year’s Safetica Technologies research, 87 % of organizations had encountered the problem of their employees using unencrypted external devices to transfer data outside of the company. This generally happens because regular users do not realize how easily the devices can be lost or stolen.

Solution: Secure the periphery

Fortunately, there are ways to significantly improve the security of external media, and computer systems in general. Here are a couple of recommendations that will substantially bolster your security:

• First of all, realize that these risks are more than real – even for you – and you should take precautions when working.

• Avoid using devices that you don’t know or that you just happen to find somewhere. They are very likely to contain a harmful code.

• Keep your system and applications up-to-date. Set your antivirus software to automatically monitor attached devices and don’t turn off your firewall.

• Encrypt the disks you use to transfer important information. In the Microsoft world, you can use BitLocker, which comes bundled with some operating systems.

• Secure your mobile phones and tablets – encrypt their content, use an antivirus and a strong screen lock (ideally a password or a finger print), don’t root them, don’t enable developer mode and do not install applications of unknown origin. Remember that active antitheft functions can significantly help in the event your device is lost or stolen. There are MDM and Mobile Security solutions available for organizations of any kind.

• Don’t forget that laptops are also devices which you use outside of home and work. Just as with phones and tablets, make sure you secure them sufficiently.

• On a company network, you can either use a device control type of system, or one that prevents removable devices from running any code.

• Last but not least, tell your acquaintances about these risks. In your friends circle substitute guidelines and regular security schoolings for simple security tips.