Sandi over at the Spyware Sucks blog pointed to this thread on Apple’s Mac forums, indicating that some Mac users have been victims of a web-based malware attack:

This has happened to me twice now, on two separate computers at work. My clipboard has been hijacked with this:

[potentially dangerous URL removed]

And once it’s in the clipboard, I can’t copy anything else over it until I’ve restarted the machine.

Several other users reported similar attacks, whether they were using Safari or Firefox as their browser.

[Update 8/19: There are also reports of this issue from users of Ubuntu, a popular distribution of Linux.]

This is a good reminder that users of operating systems other than Windows are not immune to malware or social engineering.

According to the Mac Observer, a MacBook Air was compromised via what sounds like a drive-by download style attack in a hacking competition:

On the first day of the event, contestants unsuccessfully attempted to remotely hack into the Mac, a Windows PC, and a Linux PC. On the second day, however, Mr. Miller was able to gain control over the MacBook Air in only two minutes by directing a contest organizer to visit a specially crafted Web site with the laptop.

Although the exploit code is not “in the wild” as the security industry likes to say, this still sends the message that the Mac is not immune to such attacks, even if Windows is the more commonly-exploited platform.

Apple traditionally has not been a target of hackers, yet that may be changing. Two articles this week note that increased popularity and some specific security holes in programs pose potential weaknesses.

Jeremy Kirk, at PC World, explains that increased popularity of the operating system correlates to increase likelihood for attacks. Apple has been actively releasing security updates and several companies have developed products for OS X security.

PayPal has recently requested that users transition away from Safari. The program does not provide adequate phishing protection. Michael Barrett a Senior Researcher at Paypal, and a StopBadware board member, had this to say: “Our recommendation at this point, to our customers, is use Internet Explorer 7 or 8 when it comes out, or Firefox 2 or Firefox 3, or indeed Opera.”

Just goes to show that vigilance (and downloading security updates) is important for all operating systems available.

According to security vendor F-Secure, MacSweeper is a new player to avoid in the rogue security software game, and is likely the first fraudulent anti-spyware product targeted to Mac users.

Rogue security software coerces users into downloading supposedly beneficial software that instead is either malicious or simply ineffective. This type of software uses scare tactics, such as pop-up alerts that claim spyware has been detected on a user’s machine, and usually offers a free system scan. The scan reports finding numerous problems and offers a way to fix them – if only the user will download or buy the full version of the software. Depending on the specific piece of rogue software, that full download might itself carry badware, or it might just be a wasted expense.

The emergence of rogue anti-spyware targeting Mac users could ironically be evidence of a positive trend – an increasing demand from Mac owners for security products. Regardless of your choice of operating system, it’s important to stay up to date on computer security issues that might affect your machine. One of the key ways to protect yourself is by using legitimate, frequently updated anti-virus and anti-spyware programs.

But how can you tell if a security product is safe? First, don’t let yourself be easily fooled by scare tactics or other forms of social engineering. Many rogue software pop-up ads are designed to look like official alerts from operating systems, so verify the source of a message before agreeing to a download. Look for telltale signs like misspelled words and poor grammar that you wouldn’t expect from a legitimate application, or hyperbole and sensationalist statements about what may be wrong with your computer.

Luckily, you’re not on your own in trying to tell if an application is a fraud or the real deal – you can also check the software’s reputation. Search the internet for mentions of the software you’re considering downloading, and keep your eyes out for complaints. Try searching for the name of the software along with terms like “rogue,” “malware,” “fraud” and “scam.” Find sources of recommendations you trust, and see what others are saying about the products those trusted sources recommend. Before pulling out your credit card, make sure you’ve researched the software and the vendor who makes it.

At StopBadware, we often talk with regular internet users, from the novice to the sophisticated, about internet security and precautions users can take. One comment we hear again and again is the belief that some operating systems – such as Mac OS X – are immune to badware.

The truth is, badware production is driven by the potential for monetary gain, and while the market share of the Mac operating system is not high, it’s starting to be recognized as a potentially valuable target.

The security world has long known that it was possible to create a virus that would affect Mac OS X – several researchers have demonstrated various “proof of concept” viruses that, because they were created by the good guys, were never released into the wild.

Last week saw the first public debut of a trojan apparently created for Mac OS X by organized criminal producers of badware. The trojan relies on social engineering pulls – the lure of pornography, and the confidence of Mac users – to convince users to download and install it, posing as a “codec” required to view video files.

For more on this issue, see StopBadware co-director Jonathan Zittrain’s blog post or check out the coverage at the SunBelt Software blog.