Protect against Bluetooth threats

As Bluetooth-enabled devices become increasingly pervasive, mobile users should learn how to protect themselves against new risks.
Written by Lynn Tan @ Redhat, Contributor

With Bluetooth fast becoming a commonplace feature on mobile devices, users need to be aware of vulnerabilities and learn how to protect themselves from security threats.

A study by research firm InsightExpress revealed that 73 percent of mobile device users are not acquainted with security issues that could put their mobile devices at risk, including mobile phones and Bluetooth-equipped notebooks. To these users, terms such as bluejacking, bluesnarfing or even bluebugging would probably be unfamiliar jargons.

"There are many other methods that [launch] a variety of denial-of-service attacks, and even some that could allow an attack to eavesdrop on private conversations," Ooi Szu Khiam, senior security consultant at Symantec Singapore, told ZDNet Asia in an e-mail interview. Ooi noted that "numerous instances of mobile viruses, worms and Trojan horses" have emerged in the past year.

"While none has done damage like some of the major PC malware, their rapid evolution presents an obvious cause for concern," he cautioned.

Bluejacking, also known as bluespamming, is a technique used to send anonymous text messages to mobile users via Bluetooth, Ooi explained. "Phones that are Bluetooth-enabled can be tweaked to search for other handsets that will accept messages sent via Bluetooth."

"Despite the name, it doesn't hijack the phone or suck off the information. It simply presents a message, similar to e-mail spam. The recipient can ignore the unsolicited message, read it, respond or delete it," he said. "While bluejacking can be an extremely annoying onslaught of unsolicited messages, it is generally a minimal security risk."

Bluesnarfing, however, is a more dangerous technique that can allow a malicious hacker to access information stored on a mobile device without its user's knowledge, said Ooi.

"This technique takes advantage of a security flaw, [inherent] in some older versions of Bluetooth-enabled handsets, that could allow an attacker to access and copy data stored on the device without the user's knowledge," he said. The Symantec executive noted that it is still possible to connect to such devices even if the users have configured their devices to be in "non-discovery" mode, where the device remains hidden when someone searches the vicinity for Bluetooth devices.

"Any potentially valuable information stored on a phone, such as address books, calendars, e-mail and text messages, are at risk in a bluesnarfing attack," Ooi said.

A third threat, and possibly the most deadly of the three risks, is bluebugging, he said. This technique allows attackers to access mobile phone commands using Bluetooth technology, without notifying or alerting the device owner, he noted.

"This vulnerability allows the hacker to initiate phone calls, send and receive text messages, read and write phonebook contacts, eavesdrop on phone conversations and connect to the Internet," Ooi explained. "As with all the attacks, the hacker must be within a 10-meter range of the [targeted] phone."

However, unlike bluesnarfing which simply provides attackers access to personal information on the device, bluebugging allows the attacker to take control of a device, he said.

To ensure their wireless devices are well-protected, he noted, users can equip their gadgets with mobile security products such as Symantec Mobile Security Suite 5.0, which include antivirus, firewall, anti-SMS spam and data encryption technologies, that are easy to deploy, manage and maintain.

"This kind of layered security can not only mitigate the unique security risks of mobile devices, but can also enable companies to more easily and cost effectively comply with internal security policies and external regulations," Ooi said.

He highlighted four tips on how mobile users can protect their Bluetooth-enabled devices:

Stay offline
Turn off features that you are not using. If you have a Bluetooth-equipped device and do not need the function, then don't turn it on.

Stay invisible
If you are using the Bluetooth function and don't require your device ID to be visible to others, make sure the device's visibility setting is set to "hidden" so malicious hackers will not be able to scan and search for it.

Verify incoming transmission
Do not accept and run attachments from unknown sources unless you are expecting them.

For example, if you receive a message to install an application and you don't know its origin, don't run it.

Use passwords
Ideally, use passwords with a large number of digits.

A four-digit PIN or password can be broken in less than a second, a six-digit PIN in about 10 seconds, while a 10-digit PIN would likely take weeks to crack.

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