USB memory sticks pose new dangers

Some new drives can be used to automatically run malware

The ability to use tiny USB memory sticks to download and walk away with relatively large amounts of data has already made the ubiquitous devices a potent security threat in corporate environments. Now, the emergence of USB flash drives that can store and automatically run applications straight off the device could soon make the drives even more of a security headache.

Demonstrating the potential danger, Hak.5, a security-related podcast, earlier this month showed how a USB memory stick can -- in just a few seconds -- be turned into a device capable of automatically installing back doors, retrieving passwords or grabbing software product codes.

Hak.5's "hacking framework" is called USB SwitchBlade and gives hackers a way to automate different payloads running on a USB flash drive, said Darren Kitchen, the Williamsburg, Va.-based co-host of Hak.5.

SwitchBlade takes advantage of a relatively new technology from Redwood City Calif.-based U3 LLC that allows software and applications to be executed directly from USB drives. U3's technology is designed to increase mobility by letting users store their personal desktops -- including their programs, passwords, user preferences and other data -- on a memory stick and then run it on any computer without worrying about whether those applications are installed on that system.

Unlike traditional USB flash drives, U3 memory sticks are self-activating and can auto-run applications when inserted into a system. They're part of an emerging set of "smart" flash drives becoming available from vendors such as Migo Software Inc. and Route 1 Inc.

But the same functions that allow for such mobility also give hackers another way to break into systems, said John Pescatore, an analyst at Gartner Inc. in Stamford, Conn. "Most people think of these things as storage sticks. But U3 is a little computer on a thumb drive" that could be dangerous in the wrong hands, he said.

Hak.5 has developed code that can replace parts of the original content on a U3 flash drive with a payload for "instantly" retrieving Windows password hashes when a memory stick is inserted into a computer, Kitchen said. Also available within the Hak.5 community are payloads that in seconds can retrieve AOL Instant Messenger and MSN passwords, browser histories and software products keys. Payloads can also be used to install back doors and Trojan horse programs on computers.

None of the hacker tools used in SwitchBlade are new. And security analysts have for some time now been warning that USB-connected devices such as flash drives and iPods can be used to sneak viruses and other malware into corporate environments,

But the fact that such tools can now be run automatically on a self-activating flash drive makes them far more accessible and easier to exploit, said Ken Westin, a security analyst at Centennial Software Ltd. a Swindon, England-based IT asset management company. "The combination is creating a perfect storm," he said.

The Hak.5 demonstration again highlights the need for companies to adopt holistic policies for managing USB ports, Pescatore said. "There is a growing awareness of this problem and a desire to do more port control," he said. The focus, however, should not just be on preventing data leaks but should also address other potential threats, he said.

The availability of such exploits also highlights the need for companies to disable the Windows AutoRun feature and limit administrative privileges on end-user systems. Kitchen said. One mitigating factor is that physical access to a computer is still required for someone to carry out an attack using USB drive, he said.

There are several options available to enterprises for securing USB ports on users' systems, said Jonathan Singer, an analyst at Yankee Group Research Inc. in Boston. Companies, for instance, can choose to disable USB ports through group policy management -- either on their own or through third-party vendor tools, he said. But that doesn't allow for a great deal of "granularity by system or by user," he said. Several tools are also available from vendors such as Centennial, SecureWave SA and SafeBoot NV, that let companies apply very granular and specific port control rules, he said.

Companies also need to pay attention to educating users about the potential security risks posed by USB flash drives he said.

"If you have sensitive data, you might want to institute some sort of USB control -- especially if you are in a regulated industry," Singer said. "You can have a user walk away with a whole bunch of information, or someone's PCs could get owned by a USB device they picked up in a parking lot," he said.

Copyright © 2006 IDG Communications, Inc.

7 inconvenient truths about the hybrid work trend
Shop Tech Products at Amazon