More Sony USB drives open to rootkits

A possible new Sony rootkit scandal continues to gather momentum after a second line of USB drives sold by Sony Electronics, that use rootkit tactics to hide files, has been identified.

Hackers using just one of the package's files can mask their attack code from some security scanners, said Mikko Hypponen, chief research officer at Finland-based security firm F-Secure. "This new rootkit [which can still be downloaded] can be used by any malware author to hide any folder."

Earlier this week, F-Secure announced that the fingerprint-reader software included with Sony's MicroVault USM-F flash drives in the US, stores files in a hidden directory that could be used by hackers to cloak their malicious code. F-Secure noted that the USM-F models were difficult, but not impossible to find. Sony has since confirmed that the line has been discontinued.

But its replacement, the USM512FL, is widely available, and shares the rootkit-like techniques of its predecessor. "They have the same functionality in the latest as well," said Hypponen.

Sony has removed the download links for the USM-F and USM512FL software from its MicroVault support site, but Computerworld US was easily able to locate a live link - and download the software - by searching through Google's cache.

Since F-Secure disclosed Sony's newest rootkit snafu, several other research teams have confirmed the company's findings. McAfee analysts have agreed that hackers could use one of the executable files in the USB drive software to hide any folder, and all the files in that folder, from the prying eyes of security scanners.

"Alternately, [attackers] could simply hide their malicious creations in the default installation directory itself," McAfee researchers Aditya Kapoor and Seth Purdy said in a post to the Avert Labs' blog.

Kapoor and Purdy also identified FineArt Technology, a Taiwanese developer, as the maker of the fingerprint-reading MicroVault software. On its website, FineArt touts Fingerprint Disk, a suite of tools for authenticating fingerprint-access and encrypting files and folders.

"[Their] apparent intent was to cloak sensitive files related to the fingerprint verification feature included on the USB drives," said Kapoor and Purdy. "However, in this case the authors apparently did not keep the security implications in mind."

UK-based Sophos also confirmed the presence of rootkit technologies in the FineArt-created software bundled with the MicroVault drives.

Sony, meanwhile, is still looking into the claims. "We are still investigating this and are taking the issue very seriously," he said.

These latest rootkit charges are not the first to be levelled against Sony. Nearly two years ago, security researchers spotted rootkit-like cloaking technologies used by the copy-protection software that Sony BMG Music Entertainment installed on PCs when customers played the label's audio CDs. The Federal Trade Commission later alleged that Sony had violated federal law and settled with the company earlier this year. Before that, Sony paid out nearly $6 million to settle cases with the US.

The concern now is that attackers will use the FineArt/Sony files - which can still be downloaded from Sony's web site - to add invisibility to their exploits.

But in a blog posting, F-Secure's Hypponen stressed that while the MicroVault and Sony BMG cases are similar, this newest security breakdown is not as flagrant.

"The fingerprint driver does not hide its folder as 'deeply' as does the XCP [the rootkit-style software developed by Fortium Technologies for use by Sony BMG] folder," said Hypponen. "The MicroVault software probably wouldn't hide malware as effectively from [some] real-time anti-virus scanners."