Does Parallels expose Mac OS to viruses?

M

mpemburn

Member
Hi,

Please forgive me if this has already been addressed -- a search of the forum didn't reveal it to me, however.

I've just ordered a MacBook and a copy of Parallels and I'm banking on it becoming the replacement for the Windows system that has been my working platform (in one form or another) for a dozen years or more. As such, I need to know all possible "gotchas" so as to minimize the possibility that I won't be able to work with critical applications that run only in Windows.

Not long ago, I encountered a blog article that suggested that recent updates to Parallels to make the Windows VM integrate more tightly with OS X has exposed critical Mac files to viruses brought in through Windows. They suggest running both a Windows anti-virus and a Mac-based anti-virus (like ClamAV, I think). Is this a real threat or just a conclusion the blogger jumped to without sufficient information? I'll add a link to the blog if I can find it again.

My thought is that if you use email and browsers only under OS X and reserve your use of Windows apps to those that are not web-aware, you've virtually eliminated the common vectors for viruses. Does this make good sense?

Thanks in advance,

Mark
 
If you do not use your Windows installation to access the web you have nothing to worry about. However, how do your intend to obtain and install Windows and program updates? How do you intend to register your programs?

I use my Windows installation pretty much as you intend. However, there are times when you just need to access the web via Windows. Like when a web site does not function properly in OSX, you might need to use Internet Explorer.

Do yourself a favor and install Norton AV or your favorite anti-virus program on the Windows side. You'll me happy you did.

Lew
 
The latest Parallels has a feature called shared folders. If it is enabled, a windows virus running in your Windows VM might gain access to your OS/X files and may be able to read, alter or delete them. Virus running in Windows cannot be detected or removed by AV software running in OS/X. You need to install AV software in Windows.
 
Thanks for your replies!

Here's a link to the article I mentioned:

Perils in Parallels?

. . . it says essentially what sidssp wrote.

Lew: Yes, I see what you're saying here but my plan is to use Parallels/Windows as a "bridge to the past". My use of it will diminish over time as I phase out the legacy applications I wrote in Access/VB and find replacements for the crucial things like the HomeSite HTML editor that has been my life-blood since it was freeware back in the mid-90's. I fear that Microsoft may issue a "critical update" someday soon that will kill its ability to run under Parallels (though this is probably just my paranoia showing), so I'll turn off the Windows Update feature. I've been using AVG Free on all of my Windows machines and will continue to use it when I migrate.

Regards,

Mark
 
If you have enabled global sharing in Parallels then a Windows malware has all the same access to OS X that you have. A well crafted Windows malware can install a new malicious vm on your system, copy all your vm's to a remote site where they will be perfectly runnable, modify your shell startup script to do just about anything that can be scripted the next time you open a terminal window, and it can write files to unusual areas of your OS X hard drive where you may not be looking for later use. Downloading your entire OS X home directory would be trivial. Executive summary: Yes Parallels exposes the Mac to viruses, but no longer by default. Global sharing is disabled by default but this was not always the case.
 
mpemburn said:
Thanks for your replies!

Here's a link to the article I mentioned:

Perils in Parallels?

. . . it says essentially what sidssp wrote.
Click to expand...

And I think you'll find a paragraph or two that I wrote there.

I fear that Microsoft may issue a "critical update" someday soon that will kill its ability to run under Parallels (though this is probably just my paranoia showing), so I'll turn off the Windows Update feature.
Click to expand...

Microsoft did this before then it fiddled the code in Windows 3.1 so it would no longer run in OS/2. They will do what ever is legal to protect their product.
 
Active little forum, this!

Thanks, dkp. I'll certainly want Windows to share certain folders but I'll restrict them in the same way I'd do for another machine on the network.

As an aside and going strictly from memory: I was running OS/2 on my home machine in the early to mid-90s when it was the only affordable true multitasking OS available on the Intel box. What killed it was the release of Windows 95. When it became obvious (because of the bad blood between Microsoft and IBM) that there would never be a compatibility mode (or whatever they called it then) for 32-bit Windows apps in OS/2 and little hope for serious native OS/2 32-bit developments, most OS/2 users jumped ship. I went right to NT 3.51. When MS disabled Windows 98 under OS/2, it was just out of pure spite since hardly any desktop machines were running it by then anyhow.

We hates Microscourge, we does! Down with the Evil Empire! Up with Open Source!

Mark
 
I would run antivirus on both. I am currently running AVG from Grisoft (free copy) on Windows and Intego VirusBarrier X4 on the Mac.

In reality, Windows is very suceptible to viruses unless you don't plan to use e-mail, Internet Explorer, Microsoft Office, or the Internet.

The Mac is less of a target, but if you run Entourage for Word, Excel etc. or Java you can easily pick up a virus. As Macs get more market share, they will become bigger targets
 
The whole issue is basically the same as having Windows and OS X boxes running concurrently in a network. Nothing special, really. Windows box (analogous to Parallels VM) is always subject to its own can of worms. If you let your OS X box share all or parts of its disk contents to the Windows box (analogous to the Shared Folder feature) then obviously a virus or trojan can attack this vector. At least any Windows executable won't generally run on OS X, which sort of mitigates spreading, but the files themselves are still vulnerable if you're not careful.
 
wesley said:
The whole issue is basically the same as having Windows and OS X boxes running concurrently in a network. Nothing special, really. Windows box (analogous to Parallels VM) is always subject to its own can of worms. If you let your OS X box share all or parts of its disk contents to the Windows box (analogous to the Shared Folder feature) then obviously a virus or trojan can attack this vector. At least any Windows executable won't generally run on OS X, which sort of mitigates spreading, but the files themselves are still vulnerable if you're not careful.
Click to expand...

You don't need a Windows executable to run in OS X - you only need a common script. Perl will do. I haven't seen 3.0 yet so this is just speculation, but 3.0 apparently empowers associations between Windows applications and OS X files, and vice versa. If a Windows malware can cause an association to be developed for OS X's Perl to launch a Perl script then there's no stopping what can be done. Regardless of that possibility, a trivial Windows malware can tack on a single line of code to your .bashrc file that launches anything it wants the next time you open a bash shell. At that point it owns your Mac. Probability of it actually happening? You plan for a 100% chance it will, and hope it doesn't. Feeling lucky?
 
Hi All,

Hey -- the MacBook arrived this afternoon and I installed my Windows setup via Transporter. It took about three hours to move the half-full 80 GB disk. It didn't work right away and I had to boot into Safe Mode to disable the startup options (in case Start/Run doesn't appear, you can use the Apple Command + R -- took a while to find that gem!). A few more reboots and I was looking at a teeny-weeny version of my Windows XP Pro desktop! It needed to be reactivated but that worked flawlessly using the "via Internet" option. Took less than a minute.

I'm still trying to get things figured out. Coherence mode doesn't appear to work and I'm not finding any help by searching so I may need to post another topic. I sometimes have trouble switching away from Parallels and back to Mac -- had to shut Windows down the last time around.

Thanks again,

Mark
P.S. The Parallels disk that came with the system is build 3188
 
Have you installed Parallels Tools?

If not, click Actions/Install Parallels Tools while running your Windows VM. This will give you a chance to set up Coherence and Mouse Synchronization, among other things. You may want to read the manual on Parallels Tools.
 
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