MacPro4,1 network ports shutting down.

[PinkyMacGodess]

I've got a strange problem. The net dropped earlier today. I did all the usual stuff, and couldn't get it back. I switched to the second NIC and the net was up, and now it's down. I'm on the wireless now, but am wondering if it's going to go too...

Any *known* malware or other nasty that might take out NIC's?

It's got me stumped. How could the two NIC's die within hours of each other, and then what? Are there any network cards for the old 'I Weigh As Much As A Car Engine' Mac Pro's?

Thanks in advance...

Here is the log entries that might be applicable:

6/5/14 1:23:39.069 PM com.apple.preference.network.remoteservice[501]: Bogus event received by listener connection:
<error: 0x7fff71b5db50> { count = 1, contents =
"XPCErrorDescription" => <string: 0x7fff71b5de60> { length = 18, contents = "Connection invalid" }
}

...

6/5/14 1:23:59.120 PM configd[18]: network changed: v4(en0-:10.0.0.94) DNS- Proxy- SMB-
6/5/14 1:23:59.125 PM netbiosd[147]: network_reachability_changed : network is not reachable, netbiosd is shutting down​