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Infected USB keys a threat to business IT networks, Sophos warns

Businesses have been warned to remain wary of stray USB keys after an experiment conducted by security firm Sophos found that a majority of random keys left on public transported contained malicious software. The experiment comes just 18 months after computer giant IBM suffered an embarrassing failure last year when a small number of USB […]
Patrick Stafford
Patrick Stafford

Businesses have been warned to remain wary of stray USB keys after an experiment conducted by security firm Sophos found that a majority of random keys left on public transported contained malicious software.

The experiment comes just 18 months after computer giant IBM suffered an embarrassing failure last year when a small number of USB keys handed out at its Australian conference were confirmed to have contained a piece of malware.

In Sophosโ€™ new experiment, the company obtained 50 USB keys that were left in the lost and found section of Sydneyโ€™s CityRail system. It then examined each one โ€“ 66% were found to have contained at least one piece of malware.

Sophos head of technology in Asia-Pacific, Paul Ducklin, says he was surprised the number of infected keys was so high.

โ€œItโ€™s not dramatic, itโ€™s not the end of the world, but I was surprised. I thought itโ€™d probably be about 25%, but when it was two-thirds, I thought, this doesnโ€™t reflect very well on our collective attitude to malware.โ€

The other surprising find was that none of the keys appeared to have any sort of encryption.

โ€œEven when there were files on these keys that could have given away limited information, there was no encryption. I would have been able to find out some information about what was going on here.โ€

โ€œAt some point, the owners of these keys that are sharing a whole photo album or other information, they should have thought that all of this information could have revealed some private details.โ€

At least one of the keys contained a copy of the Conficker virus โ€“ a major virus that brought down thousands of computers in the past few years, including those in Government departments worldwide.

And while Ducklin says the experiment isnโ€™t a major one โ€“ and he admits the sample size is small โ€“ he nevertheless says itโ€™s a reminder for businesses they need to lock down their networks from foreign USB keys that donโ€™t have any sort of encryption.

โ€œThe primary way malware gets into organisations is by spreading through networks. It can spread via the internet, but the main way it occurs is through USB keys.

โ€œUSB keys are doing a lot of dirty work and thatโ€™s why businesses need to watch out for them.โ€

Ducklin also says any individuals using a USB key need to apply some sort of encryption, even if theyโ€™re using a Mac.

โ€œThere may be some people who think they donโ€™t need encryption or virus software because theyโ€™re using a Mac. But the keys we found that appeared to have come from Mac users โ€“ at least some of them were infected.โ€

โ€œNone appeared to be using encryption. Somehow, I think if the people who owned these keys knew they were being analysed, they would change their minds.โ€